Monday Morning, October 21, 2019 2D Materials between 800 °C and 900 °C in UHV. The MoS2 crystal shapes are stable Room A216 - Session 2D+EM+MI+NS-MoM upon annealing until the residual MoO3 particles evaporate at above 1000 °C. This infers that any triangular crystals that look intact under low- Properties of 2D Materials including Electronic, Magnetic, magnification optical microscopy and SEM may not mean pristine MoS2. Mechanical, Optical, and Thermal Properties I 9:00am 2D+EM+MI+NS-MoM3 3D Printed and Injection Molded Polymer Moderator: Sanghoon Bae, Massachusetts Institute of Technology Matrix Composites with 2D Layered Materials, Sangram Mazumder, 8:20am 2D+EM+MI+NS-MoM1 Extreme Fatigue Life of Graphene, Teng University of North Texas; J.A. Catalan, University of Texas at El Paso; N. Cui, S. Mukherjee, P.M. Sudeep, G. Colas, J. Tam, University of Toronto, Hnatchuk, I. Chen, University of North Texas; P. Perez, University of Texas Canada; P.M. Ajayan, Rice University; C.V. Singh, Y. Sun, T. Filleter, at El Paso; W. Brostow, A.B. Kaul, University of North Texas University of Toronto, Canada The two-dimensional layered materials (2DLMs), MoS2 and WS2, as well as Materials can fail when subjected to cyclic loading at stress levels much three-dimensional (3D) graphite were infused in thermoplastic polymer lower than the ultimate tensile strength or yielding limit, which is known as matrices, specifically acrylonitrile butadiene styrene (ABS) and mechanical fatigue. Understanding the fatigue behavior is critical for any polyethylene terephthalate glycol (PETG). Two techniques were explored emerging material in order to evaluate its long-term dynamic reliability. for the production of these composites into dog-bone structures for Two-dimensional (2D) materials have been widely applied to mechanical mechanical testing, which included 3D printing and injection molding. The and electronic applications, where they are commonly subjected to cyclic ductility of the composites was generally seen to decrease with the stress. However, the fatigue life and underlying damage mechanisms of addition of the fillers compared to the otherwise ductile polymer matrix these atomically thin, nearly defect-free, materials are unknown. Here we counterparts. Also, changes in Young’s modulus, yield and tensile show the first fatigue study of freestanding 2D materials, in particular strengths, as well as percent strain at fracture, were analyzed as a function graphene and graphene oxide (GO). Monolayer and few layer graphene of filler loadings. The effect of processing technique on microstructures and GO were found to all exhibit ultrahigh fatigue life of more than one was also investigated by scanning electron microscopy of the fracture billion cycles at large stress level in the GPa range. Such a remarkable surfaces which revealed the presence of microstructural defects in the fatigue life is higher than that of any material reported to date at similar form of voids in the injection molded samples, which act as stress stress levels. Graphene exhibits global and catastrophic fatigue failure concentrators in the composite samples. Additionally, dynamic friction data preceded by bond reconfiguration near the defective site due to of the composites was measured in an attempt to exploit the traditional, inhomogeneous charge distribution and higher potential energy. Graphene inherent solid phase lubricating properties of the 2DLMs. Graphite was can fracture under cyclic loading but without progressive damage, which is indeed seen to lower dynamic friction in case of 3D printed PETG and distinct from the fatigue failure mechanism of any other materials. The injection molded ABS. Also, MoS2 and WS2 were found to reduce friction in presence of functional groups on GO imparts a local and progressive 3D printed PETG and ABS. Graphite being an intrinsically good conductor, fatigue damage mechanism, which fits the macroscopic fatigue convention. while the other 2DLMs explored, specifically MoS2 and WS2 given their The extraordinary fatigue life was found to diminish significantly when the semiconducting nature, can also be used as avenues for introducing material is scaled up in thickness (10s of layers). This work not only electrical conductivity within these otherwise insulating parent polymer provides new fundamental insights into the widely observed fatigue matrices. Thermal conductivity was also found to increase in both ABS and enhancement behavior of graphene-embedded nanocomposites, but also PETG composites containing graphite, MoS2 and WS2, irrespective of their serves as a starting point for the mechanical dynamic reliability evaluation processing routes. The use of 2DLM-based polymer composites remains an of other 2D materials. area that is bound to open up avenues for a wide range of applications in the future related to wearable electronics and sensors with low-cost 8:40am 2D+EM+MI+NS-MoM2 Epitaxial Growth and Thermal Degradation additive manufacturing approaches. of Monolayer MoS2 on SrTiO3 Single Crystal Substrates, Peiyu Chen, W. Xu, Y. Gao, P. Holdway, J.H. Warner, M.R. Castell, University of Oxford, UK 9:20am 2D+EM+MI+NS-MoM4 Semiconducting WS2 and h-BN Inks for Printing Optically-active Nanodevices, Jay A. Desai, University of Texas at Monolayer MoS2 crystals grown on amorphous substrates such as SiO2 are El Paso; S. Mazumder, A.B. Kaul, University of North Texas randomly oriented. However, when MoS2 is grown on crystalline substrates, the crystal shapes and orientations are also influenced by their We present our work on dispersions of WS2 and h-BN using cyclohexanone epitaxial interaction with the substrate. In the first part of this talk, we and terpineol (C/T) as the solvent to subsequently print prototype nanodevices. Current-voltage measurements, Raman spectroscopy, and present the results from chemical vapor deposition growth of MoS2 on photoluminescence spectroscopy were used to characterize the properties three different terminations of single crystal strontium titanate (SrTiO3) of these inks produced by various sonication techniques such as horn tip substrates: (111), (110), and (001). On all three terminations of SrTiO3, the sonication, magnetic stirring and shear mixing. Both photodetector and monolayer MoS2 crystals try to align their <2 -1 -1 0>-type directions (i.e., the sulfur-terminated edge directions) with the <1 -1 0>-type directions on capactive heterostructure devices were formed with these materials. From this analysis, the photoresponsivity and detectivity of the graphene-WS2- SrTiO3. This arrangement allows near-perfect coincidence epitaxy between graphene heterostructure devices were calculated to be ~ 0.86 A/W and ~ seven MoS2 unit cells and four SrTiO3 unit cells. On SrTiO3(110), this even 13 distorts the crystal shapes and introduces an additional strain detectable by 10 J, respectively. Capacitance-voltage (C-V) and C-frequency (f) photoluminescence (PL). Our observations can be explained if the measurements were also conducted, where the V was swept from – 6 V to + 6 V, while the change in C was measured from f ~ 20 kHz up to 3 MHz to interfacial van der Waals (vdW) bonding between MoS2 monolayers and gain insights into the nature of the graphene-WS2 interface. An all-inkjet- SrTiO3 is greatest when maximum commensuration between the lattices is achieved. Therefore, a key finding of this study is that the vdW interaction printed graphene-h-BN-graphene capacitors were fabricated and leakage 2 current density, JLeakage, of up to ~ 0.072 µA/mm and capacitance density of between MoS2 and SrTiO3 substrates determines the supported crystal 2 shapes and orientations by epitaxial relations. up to ~ 2.4 µF/cm is reported. Finally, the influence of temperature, frequency, and LED illumination on the performance of the graphene-h-BN- Monolayer MoS2 is also a wide-bandgap semiconductor suitable for use in based capacitor is explored with the help of capacitance density-voltage high-temperature electronics. It is therefore important to understand its measurements at different parameters to promote the all-inkjet-printed thermal stability. In the second part, we uncover the thermal degradation capacitor for photosensitive detector applications. behavior of monolayer MoS2 supported on SrTiO3 in ultrahigh vacuum (UHV) because of sulfur loss. MoS2 was found to degrade on the (111), 10:40am 2D+EM+MI+NS-MoM8 Engineering Interfaces in the Atomically- (110), and (001) terminations of SrTiO3 substrates in a similar way. The Thin Limit, Deep Jariwala, University of Pennsylvania INVITED sulfur loss begins at 700 °C, at which point triangular etch trenches appear The isolation of a growing number of two-dimensional (2D) materials has along the sulfur-terminated edge directions of the MoS2 crystals (in inspired worldwide efforts to integrate distinct 2D materials into van der scanning tunneling microscopy). The sulfur vacancies can be filled Waals (vdW) heterostructures. While a tremendous amount of research byannealing the crystals in a hot sulfur atmosphere, and the optical activity has occurred in assembling disparate 2D materials into “all-2D” van properties (by Raman spectroscopy and PL) of monolayer MoS2 can nearly der Waals heterostructures, this concept is not limited to 2D materials be fully recovered. At higher UHV annealing temperatures, the remaining alone. Given that any passivated, dangling bond-free surface will interact Mo is oxidized by the SrTiO3 substrates into MoO2 and MoO3. The initial with another via vdW forces, the vdW heterostructure concept can be sulfur loss and the formation of MoOx are confirmed by X-ray extended to include the integration of 2D materials with non-2D materials photoelectron spectroscopy. The sulfur annealing no longer takes effect that adhere primarily through noncovalent interactions. I will present our when all the Mo has been oxidized, which happens at a temperature work on emerging mixed-dimensional (2D + nD, where n is 0, 1 or 3) Monday Morning, October 21, 2019 1 8:20 AM Monday Morning, October 21, 2019 heterostructure devices. Two distinct examples of gate-tunable p-n Actinides and Rare Earths Focus Topic heterojunctions with anti-ambipolar field efect will be presented. The anti- Room A215 - Session AC+LS+MI-MoM ambipolar field effect observed in the above systems is also shown generalized to other semiconducting heterojunction systems and extended Magnetism, Complexity, Superconductivity, and Electron over large areas with practical applications in wireless communication Correlations in the Actinides and Rare Earths circuits. Recent work on high performance 2D/3D triodes will also be Moderators: Krzysztof Gofryk, Idaho National Laboratory, Ladislav Havela, presented. Charles University, Prague, Czech Republic The second part of talk will focus on engineering interfaces on photovoltaic devices from 2D semiconductors such as transition metal dichalcogenides 8:20am AC+LS+MI-MoM1 Possible Structural Quantum Phase Transition (TMDCs).High efficiency inorganic photovoltaic materials (e.g., Si, GaAs and in UCr2Si2 Accessed Through Cr → Ru Chemical Substitution, Ryan GaInP) can achieve maximum above-bandgap absorption as well as carrier- Baumbach, Florida State Universityy INVITED selective charge collection at the cell operating point. Experimental Materials with intertwined magnetic, electronic, and structural degrees of demonstration of light confinement in ultrathin (< 15 nm) Van der Waals freedom often can be tuned (e.g., using pressure or chemical substitution) to induce novel behavior, including unconventional superconductivity. semiconductors (MoS2, WS2 and WSe2) leading to nearly perfect absorption will be demonstrated concurrently with record high quantum efficiencies. Examples include the cuprates, iron based superconductors, and Ongoing work on addressing the key remaining challenges for application lanthanide/actinide-based compounds, and despite the their diversity of of 2D materials and their heterostructures in high efficiency photovoltaics structure, chemistry and interaction mechanisms, their individual phase which entails engineering of interfaces and open-circuit voltage will be diagrams often conform to a semi-universal format that features a presented in addition to on going work on probing of buried quantum phase transition. As a result, there have been prolonged efforts metal/semiconductor interfaces with sub 50 nm resolutions as well as near to develop new families of materials based on this paradigm. Even so, there field luminescence spectroscopy. I will conclude by giving a broad still are few examples of f-electron intermetallics that combine both perspective of future work on 2D materials from fundamental science to magnetic and structural quantum phase transitions. In this talk, we will applications. present results from recent efforts to tune the ordered states of UCr2Si2, which is a Kondo lattice metal with antiferromagnetic ordering near TN ≈ 24 11:20am 2D+EM+MI+NS-MoM10 Ultrasoft Slip-mediated Bending in Few- K and a structural phase transition near TS ≈ 200 K. In particular, we will layer Graphene, Jaehyung Yu, E. Han, E. Annevelink, J. Son, E. Ertekin, P.Y. focus on the influence of Cr to Ru chemical substitution, where we find that Huang, A.M. van der Zande, University of Illinois at Urbana-Champaign both TN and TS are rapidly suppressed towards separate quantum phase A challenge and opportunity in nanotechnology is to understand and take transitions. The impact of the quantum phase transitions on the structural, advantage of the breakdown in continuum mechanics scaling laws as magnetic, and electronic properties will be examined in detail. systems and devices approach atomic length scales. Such challenges are particularly evident in two-dimensional (2D) materials, which represent the 9:00am AC+LS+MI-MoM3 Dynamic Spin Transport in Antiferromagnetic ultimate limit of mechanical atomic membranes as well as molecular Insulators: Angular Dependent Spin Pumping in Y3Fe5O12/NiO/Pt Trilayers, electronics. For example, after more than a decade of study, there is no Fengyuan Yang, The Ohio State University INVITED consensus on the bending modulus of few layer graphene, with measured In recent years, pure spin transport driven by ferromagnetic resonance and predicted values ranging over two orders of magnitude, and with (FMR) spin pumping or a thermal gradient has attracted intense interest different scaling laws. However, comparing these studies is challenging and become one of the most active frontiers in condensed matter and because they probe very different and often fixed curvatures or materials physics. Extensive research efforts have demonstrated pure spin magnitudes of deformation. To unravel the discrepancy, a systematic currents in a broad range of materials, which enrich our understanding of measurement of bending stiffness versus deformation is needed. The dynamically-driven spin transport and open new paradigms for energy- results have practical implications on predicting and designing the stiffness efficient, spin-based technologies. Antiferromagnetic (AF) insulators of many 2D mechanical systems like origami/kirigami nanomachines, possess various desired attributes, such as low loss and high speed up to stretchable electronics from 2D heterostructures, and resonant THz frequencies, for future spintronic applications. nanoelectromechanical systems. To probe the dynamic spin transport phenomena and the underlying In this study, we combine atomistic simulation and atomic scale imaging to mechanisms in AF insulators, we use high-quality Y3Fe5O12 (YIG) epitaxial theoretically and experimentally examine the bending behavior of few- thin films excited by FMR as a source to inject spins into AF insulator NiO layer graphene. First, we experimentally probe the nanoscale bending by layers and detect the transmitted spin current using inverse spin Hall effect laminating few-layer graphene over atomically sharp steps in boron nitride (ISHE) signals in YIG/NiO/Pt trilayers [1, 2]. We observed robust spin and imaging the cross-sectional profile using aberration-corrected STEM. currents from YIG to Pt across AF insulators, which initially enhances the Second, we use DFT simulations to examine the bending of few-layer ISHE signals and can transmit spin currents up to 100 nm thickness, graphene under compression. By measuring the nanoscale curvatures, we demonstrating highly efficient spin transport through an AF insulator extract the simulated and experimental bending modulus while varying carried by magnetic excitations. Recently, we studied the angular both the number of layers and the degree of nanoscale curvature. dependence of spin pumping in a series of YIG/NiO/Pt trilayers as the orientation of the applied magnetic field is rotated out of plane [3]. A We find remarkable agreement between the theory and experiment and simple sinusoidal angular dependence of VISHE has been viewed as a observe an unexpected curvature dependent bending stiffness of few-layer signature of spin pumping. Surprisingly, we observe an extensive plateau in graphene that deviates from continuum scale bending mechanisms. We the VISHE vs. θH plots with a pronounced peak feature at an out-of-plane find that the bending stiffness of few layer graphene versus curvature angle of 45° to 60° when the measurement temperature is close to the corresponds with a gradual change in scaling power with thickness from Néel temperature (TN) of NiO. This phenomenon can be understood as cubic to linear. We find that the transition in scaling behavior originates arising from the competition between the exchange coupling at the from a transition from shear, slip and the onset in superlubricity between YIG/NiO interface, the easy-plane and in-plane easy-axis anisotropies of the graphene layers at the van der Waals interface, verified by a simple NiO, and the effect of the applied magnetic field. While insulating Frenkel-Kontorova model. Our results provide a unified model for the antiferromagnetic films can efficiently transmit spin currents and show bending of 2D materials and show that their multilayers can be orders of promise for integration in spintronic devices, the underlying physics of spin magnitude softer than previously thought, among the most flexible ordering and dynamics is richer than currently understood. electronic materials currently known. References: 1. H. L. Wang, et al.PRB 91, 220410(R) (2015). 2. H. L. Wang, et al.PRL113, 097202 (2014). 3. Y. Cheng, et al.PRB 99, 060405(R) (2019) 9:40am AC+LS+MI-MoM5 Pressure Studies of Strongly Correlated Phases in Rare Earth Compounds, Rena Zieve, University of California, Davis INVITED Various strongly correlated materials have complex low-temperature phase diagrams, exhibiting magnetism and superconductivity as well as spin glass,

Monday Morning, October 21, 2019 2 8:20 AM Monday Morning, October 21, 2019 non-Fermi liquid, and other behaviors. Since each material has its own 6. Energy, electricity, and nuclear power: developments and projections-25 quirks, determining the underlying universal influences has been years past and future, International Atomic Energy Agency, Vienna, challenging. Pressure is a key tool in these efforts, since pressure can tune 2007,www-ub.iaea.org/mtcd/publications/pdf/pub1304 the interactions within a material without changing its chemical 7. F. Gupta, A. Pasturel, G. Brillant, Phys. Rev. B 81, 014110(2010). composition or impurities. I will discuss how hydrostatic or uniaxial pressure can probe strongly correlated materials by changing valence, 8. J.G. Tobin and S.-W. Yu, Phys. Rev. Lett, 107, 167406 (2011). breaking crystal symmetry, or altering the dimensionality of the electron 11:20am AC+LS+MI-MoM10 Optimizing the Magnetic Performance of system. I will draw examples from various rare earth compounds. Finally, I Tetragonal ReFe12-xMx Phases by First Principles Computational will mention recent pressure application techniques that expand the range Simulations, Heike Christine Herper, O.Y. Vekilova, P. Thunström, O. of possible characterization measurements. Eriksson, Uppsala University, Sweden 10:40am AC+LS+MI-MoM8 Fermi Surface Reconstructions and Transport The increase of environmentally friendly energy production is coupled to Properties in Heavy-fermion Materials, Gertrud Zwicknagl, Institut f. an increasing demand for new magnetic materials. Especially, new Rare Mathemat. Physics, TU Braunschweig, Germany earth (Re) lean permanent magnets are highly sought after as possible The search for new types of exotic topological orders has recently rekindled replacement for high-performance magnets based on Nd-Fe-B and Dy to the interest in Fermi surface reconstructions. Of particular interest are limit costs and supply risk. In this context the tetragonal 1:12 phase Electronic Topological (Lifshitz) transitions where the number of FS sheets (TmMn12) which contains 35% less Re than commercial Nd-Fe-B magnets changes abruptly under the influence of external parameters like chemical are rediscovered. To stabilize this phase with light Re and Fe instead of Mn doping, pressure, or magnetic field. Lifshitz transitions (LTs) are generally a nonmagnetic phase stabilizing element is needed but this degrades the associated with the presence of critical points in the electronic band magnetic performance. structure, i. e., maxima, minima, or saddle points whose presence follows To identify new 1:12 phases being suitable for permanent magnet directly from lattice periodicity. As their separation from the Fermi energy applications materials design based on computational simulations has is of the order of the bandwidth the critical points usually do not a ect the become an important tool. Here we focus on ReFe12-xMx. with Re = Y, Ce, low temperature behavior. In heavy-fermion materials, however, magnetic Nd, Sm and M = Ti and V. We use state of the art density functional theory fields can drive LTs which are reflected in pronounced anomalies in methods (VASP; full potential LMTO (RSPt)). The phase stability and the thermodynamic and transport properties. Here we demonstrate that the magnetic properties were calculated depending on the M concentration. magnetic field-dependent anomalies in the Seebeck coefficient provide Aiming to reduce the Re amount we monitor the performance depending detailed information not only on the critical points, i. e., their character and on the Nd/Y ratio. position relative to the Fermi energy but also on the quasi-particle The key quantities are the magnetocrystalline anisotropy (MAE) and the dispersion in the vicinity of the critical points, i. e., the effective mass magnetization. To capture the correct magnetic behavior, it is crucial to tensor. For lanthanide-based HFS, the theoretical analysis is based on describe the localization of the 4f electron properly for each Re. While for Renormalized Band (RB) structure calculations assuming that the heavy Sm-based systems the spin-polarized core approximation is sufficient to quasiparticles result from a Kondo effect. For U-based HFS, on the other describe the localized 4f electrons, it fails for Nd, e.g. the low temperature hand, we adopt the "dual nature" model which allows for a microscopic MAE of NdFe11Ti would be uniaxial instead of conic. Using a DFT+U description of the heavy bands. The calculated Lifshitz transitions approach with U = 5 eV, J = 1.1 eV for NdFe11Ti reproduces the reproduce the observed positions of anomalies in the Seebeck coecients experimentally observed behavior. Ce is special since the uniaxial MAE of surprisingly well. CeFe11Ti is obtained independent from the treatment of the 4f electron. However, an analysis of the hybridization function analogue to [1] shows 11:00am AC+LS+MI-MoM9 Direct Measurement the 5 f5/2 and 5 f7/2 that a spin polarized core approximation is more appropriate for Ce-based Unoccupied Density of States of UO2, James G. Tobin, University of Wisconsin-Oshkosh; S. Nowak, SLAC National Accelerator Laboratory; C.H. 1:12 phases. For a deeper insight additional studies are carried out to Booth, Lawrence Berkeley National Laboratory; E.D. Bauer, Los Alamos examine the crystal field splitting. National Laboratory; S.W. Yu, Lawrence Livermore National Laboratory; R. With SmFe11V system a new phase was found leading to an increase of the Alonso-Mori, T. Kroll, D. Nordlund, T.C. Weng, D. Sokaras, SLAC National magnetization by 17% compared to the commonly used concentrations of Accelerator Laboratory V. In view of the MAE a replacement of Nd by Y turned out to be preferable 3 In a world of ever increasing population and diminishing resources, the over a reduction of Ti. MAE values of 1.3 MJ/m ((NdY)Fe11Ti) and 1.7 3 need for abundant and inexpensive energy remains critical. [1] Despite the MJ/m (SmFe11V) are predicted [2]. The latter could already be verified in problems associated with radioactive contamination/disposal and nuclear recent experiments [2]. proliferation, electricity generated by nuclear power remains immensely Supported by the European Research Project NOVAMAG, Swedish important, [2] providing for 20% of the electrical grid of the USA and 50% Foundation for Strategic Research and STandUP for Energy. or more for several European nations. [3-6] Uranium Dioxide (UO2) is by far [1] H.C.Herper et al., Phys. Rev. Materials1, 033802 (2017) the widely used nuclear fuel for the generation of electricity. [7] Thus, a fundamental understanding of the electronic structure of UO2 is crucial, if [2] A. M. Schönhöbel et al., JALCOM 786, 969 (2019) only to provide the best theoretical models for its disposal and storage. [7, 11:40am AC+LS+MI-MoM11 Optical Excitation Effect on 8] Magnetodielectric and Photodielectric Properties of Rare Earth doped Using High Energy Resolution Fluorescence Detection (HERFD) in a ZnO:Na Nanoparticles, Mohammed Bsatee, F.P.N. Inbanathan, Ohio Resonant Inelastic Scattering (RIXS) experiment and electric dipole University; R. Martínez, University of Puerto Rico; H. Huhtinen, University selection rules, the U 5f5/2 and U 5f7/2 Unoccupied Densities of States of Turku, Finland; R. Palai, University of Puerto Rico (UDOS) were determined. Significant changes were observed in going from There have been ongoing efforts in developing rare earth (RE) ions doped UF4 (localized, 2 5f electrons) to UCd11 (localized, 3 5f electrons), semiconductors responsive to optical and magnetic stimuli for developing consistent with the predictions of the Intermediate Coupling Model. The multifunctional devices. ZnO is considered as a promising semiconductor results for UO2 were experimentally confirmed by direct comparison with with wide range of applications in optoelectronics and spintronics due to the Bremstrahlung Isochromat Spectroscopy for Uranium Dioxide. its optical properties (i.e. direct band gap, high electron mobility, high References thermal stability, strong absorption of UV), and at the same time being an attractive host for RE doping resulting in enhanced spin polarization in 1. “Reasons for increase in demand for energy,” BBC News, ZnO:RE matrix [1]. In this project, undoped and RE ions (Er and Yb) doped https://www.bbc.com/bitesize/guides/zpmmmp3/revision/1 and co-doped ZnO:Na nanoparticles were studied with an aim to 2. Y. Guerin, G.S. Was, S.J. Zinkle, MRS Bull. 34, 10 (2009). understand recently reported magnetodielectric and photodielectric 3. Nuclear Energy Institute, Nuclear shares of electricity generation, effects stimulated by magnetic field and UV excitation stimuli [2]. After http://www.world-nuclear.org/info/nshare.html synthesizing well-defined Er and Yb-co-doped ZnO:Na by sol-gel route, 4. Eleanor Beardsley, France presses ahead with nuclear power, Nat’l Pub. evaluation of structural, optical, magnetic and electrical characteristics of Radio, http://www.npr.org/templates/story/story.php?storyId=5369610 synthesized nanoparticles was performed. Structure, morphology, and composition of the samples were analyzed by XRD and SEM showing high 5. Nuclear energy, Environmental Protection Agency, USA, quality hexagonal crystal structure. The absence of secondary phases was http://www.epa.gov/cleanenergy/energy-and-you/affect/nuclear.html confirmed by Raman spectroscopy and XPS analysis of all elements in

Monday Morning, October 21, 2019 3 8:20 AM Monday Morning, October 21, 2019

ZnO:NaErYb compound. Optical properties were investigated by optical regime. On the other hand, Permalloy (Ni81Fe19 or NiFe) is a soft magnetic reflectance spectroscopy, photoluminescence (PL), PL excitation, and PL material that has very low loss in the GHz regime, with a ferromagnetic kinetics with photons excitation energy corresponding to above and below resonance (FMR) linewidth of 10 Oe, but almost no magnetostriction. In bandgap energy. PL spectra were investigated under magnetic field of up to this work, nanoscale laminates containing alternating layers of FeGa and 2 Tesla in 7 K – 400 K temperature range. It was observed that PL spectra NiFe were fabricated via DC magnetron sputtering to combine the exhibit broad green-yellow defects emission band without NBE excitonic complementary properties of the two magnetic phases, resulting in a peak. PLE spectra revealed that both Er3+ and Yb3+ ions are optically active composite material with a small coercive field, narrow FMR linewidth, and and involved in complex energy transfer between ZnO:Na host and 4f-shall high permeability (Rementer et al., 2017). Optical magnetostriction levels of RE3+ ions dopants. PL spectra show features related to intra-shell measurements confirmed that these laminates retain the large saturation 4f-4f transitions of the Er3+ ion (at 522 nm) and Yb3+ ion (at 980 nm). It was magnetostriction of FeGa (200 µε) while enhancing the piezomagnetic observed that luminescence decay of the ZnO defect band is unexpectedly coefficient (7 ppm/Oe), allowing for optimal piezomagnetic actuation at long (> tens of 10-3 second), strongly affected by RE3+ ions doping and substantially reduced magnetic bias fields. Furthermore, multiferroic depends on the magnetic field strength when excited at 3.814 eV. In the composites incorporating these magnetic laminates were studied via presentation we will attempt to correlate reported magnetodielectric and polarized neutron reflectometry, demonstrating uniform rotation of the photodielectric properties of the Er,Yb-co-doped ZnO:Na [2] with observed individual layers’ magnetization with an applied electric field across optical characteristics. distances much larger than the exchange length of either material. References Due to the metallic nature of these FeGa/NiFe multilayer composites, [1] A.G. El Hachimi, H. Zaari, A. Benyoussef, M. El Yadari, A. El Kenz, J. Rare however, resulting devices would be inefficient due to the generation of Earths, 32, p.715 (2014).[2] R. Martinez Valdes, N. Kumar, H. Huhtinen, W. eddy currents at high frequency. To mitigate these losses, ultrathin layers M. Jadwisienczak, R Palai, MRS Adv. (2019), DOI: 10.1557/adv.2019. 66. of Al2O3 were incorporated into the multilayer materials to reduce the conductivity and mitigate the generation of eddy currents. The effect of Al2O3 thickness, FeGa:NiFe volume ratio, and multilayer architecture on the soft magnetic properties was also studied, resulting in a 50% reduction in Thin Films Division the FMR linewidth. Optimized magnetic laminates were shown to exhibit a Room A122-123 - Session TF+EM+MI+MN+OX+PS-MoM small coercive field (<20 Oe), narrow ferromagnetic resonance linewidth Functional Thin Films: Ferroelectric, Multiferroics, and (<50 Oe), and high relative permeability (>500) while maintaining excellent magnetoelastic coupling, showing great promise for the use of Magnetic Materials FeGa/NiFe/Al2O3 laminates in strain-mediated micro-scale communications Moderators: Christophe Vallee, LTM, Univ. Grenoble Alpes, CEA-LETI, systems. France, Jessica Kachian, Intel Corporation 9:20am TF+EM+MI+MN+OX+PS-MoM4 Multiferroic Gd-substituted 8:20am TF+EM+MI+MN+OX+PS-MoM1 A Room-Temperature HfO2Thin Films, John Hayden, F. Scurti, J. Schwartz, J.-P. Maria, Magnetoelectric Multiferroic made by Thin Film Alchemy, D.G. Schlom, Pennsylvania State University Megan Holtz, Cornell University INVITED Modern ferroelectric technologies utilize perovskite structured materials, Materials that couple strong ferroelectric and ferromagnetic order hold which have limited Si compatibility and modest bandgaps requiring thick tremendous promise for next-generation memory devices. Meticulous films to reduce leakage current, hindering their implementation in engineering has produced novel ferroelectric and multiferroic materials, realizable thin film devices. HfO2 has been extensively researched as a gate although known single-phase multiferroics remain limited by dielectric thin film with excellent Si processing compatibility and has antiferromagnetic or weak ferromagnetic alignments, by a lack of coupling recently been found to exhibit ferroelectricity induced by a combination of between the order parameters, or by having properties that emerge only impurity substitution, mechanical confinement by capping, intergranular well below room temperature. Here we construct single-phase multiferroic surface area, and film thickness effects. This work investigates the materials in which ferroelectricity and strong magnetic ordering are microstructural characteristics, the ferroelectric response, and the coupled near room temperature. Starting with hexagonal LuFeO3—a potential for concomitant magnetic properties in sputtered Gd:HfO2 thin geometric ferroelectric with planar rumpling—we introduce individual films. monolayers of ferrimagnetic LuFe2O4 within the LuFeO3 matrix, that is, Gd-substituted HfO2 thin films are a promising candidate as a multiferroic (LuFeO3)m/(LuFe2O4)1 superlattices. The rumpling of the LuFeO3 drives the material, due to the presence of the magnetically active Gd3+ ion. Though ferrimagnetic LuFe2O4 into a ferroelectric state, reducing the LuFe2O4 spin frustration. This increases the magnetic transition temperature to 281K for substituting with Gd is known to induce ferroelectricity in HfO2, the m=9. Moreover, the ferroelectric order couples to the ferrimagnetism, magnetic properties of Gd:HfO2 have yet to be studied in depth. In this enabling direct electric-field control of magnetism at 200 kelvin. Further, study, Gd:HfO2 films are fabricated on TaN substrates by radio frequency sputtering of a composite Gd metal and HfO2 oxide target in a mixed Ar and charged ferroelectric domain walls align at LuFe2O4 layers, resulting in charge transfer which increases the magnetic moment. We are currently O2 atmosphere. Grazing incidence x-ray diffraction is used to evaluate the pursuing higher temperature multiferroics by incorporating cubic spinels suppression of the paraelectric monoclinic phase and stabilization of the ferroelectric orthorhombic phase. Electrical polarization measurements are with high magnetic ordering temperatures, such as CoFe2O4, into the used to study the room temperature spontaneous polarization in LuFeO3 matrix. Our results demonstrate a design methodology for creating higher-temperature magnetoelectric multiferroics through epitaxial TaN/Gd:HfO2/TaN metal-insulator-metal capacitors. Surface morphology of engineering. the films is characterized using atomic force microscopy, while magnetic properties are measured by variable temperature magnetometry. Initial 9:00am TF+EM+MI+MN+OX+PS-MoM3 Magnetic Losses in magnetometry shows that Gd-substituted HfO2 exhibits remnant FeGa/NiFe/Al2O3 Laminates for Strain-Mediated Multiferroic Micro- magnetization at room temperature. Antenna Applications, Kevin Fitzell, A. Acosta, C.R. Rementer, D.J. The scalability and simplicity of Gd:HfO2, if it exhibits magnetoelectric Schneider, Z. Yao, University of California, Los Angeles; C. Dong, coupling, make it an attractive model system for future developments in Northeastern University; M.E. Jamer, D. Gopman, J. Borchers, B. Kirby, thin film multiferroics, having potential impacts for spintronics and other National Institute of Standards and Technology (NIST); N. Sun, magnetoelectronic devices. Northeastern University; Y. Wang, G.P. Carman, J.P. Chang, University of California, Los Angeles 9:40am TF+EM+MI+MN+OX+PS-MoM5 Epitaxial Growth of The ability to reduce the size of antennae would enable a revolution in Antiferromagnetic NiO Films by Off-axis Sputtering for Spintronic Devices, wearable and implantable electronic devices. Multiferroic antennae, A. Churikova, G.S.D. Beach, Massachusetts Institute of Technology; Larry composed of individual ferromagnetic and piezoelectric phases, could Scipioni, A. Shepard, J. Greer, T. Newhouse-Illige, PVD Products, Inc. reduce antenna size by up to five orders of magnitude through the efficient High-quality epitaxial growth of antiferromagnetic thin films is essential for coupling of magnetization and electric polarization via strain. This strategy future spintronic devices, as it allows small antiferromagnetic domain sizes requires a material with strong magnetoelastic coupling and acceptable and efficient electrical manipulation of domain walls via reading and magnetic losses at high frequency. writing currents. Antiferromagnetic materials are candidates for ultrafast operation due to THz antiferromagnetic spin dynamics, high packing Galfenol (Fe84Ga16 or FeGa) is a promising candidate material due to its large magnetostriction (200 µε), large piezomagnetic coefficient (5 densities due to the absence of stray magnetic fields, and stability due to ppm/Oe), and high stiffness (60 GPa), but it is highly lossy in the GHz insensitivity to external magnetic fields [1,2]. Meanwhile, the long spin Monday Morning, October 21, 2019 4 8:20 AM Monday Morning, October 21, 2019 diffusion lengths [3] and theoretically predicted superfluid transport of spin Specifically, we will discuss preparation of superlattice-like polycrystalline currents [4] in antiferromagnetic insulators are crucial for low-power PZT thin films through chemical solution depositions, polycrystalline device operation. The electrical control of magnetic spin textures has been relaxor-ferroelectric thin films (PMN-PT), and finally alternative non- thus far realized in epitaxially grown NiO on MgO substrates [5] and ferroelectric compositions, where the electric field-induced phase ferrimagnetic maghemite (γ−Fe2O3) and magnetite (Fe3O4) thin films [6]. transitions can result in substantial enhancement in thinner films, even We report the preparation of antiferromagnetic NiO thin films with (111) where traditional orientation on c-plane sapphire (1000) substrates by off-axis RF magnetron 11:20am TF+EM+MI+MN+OX+PS-MoM10 Ferroelectrics Meet Ionics in the sputtering from a NiO target. The off-axis angle was 45°, and the sputtering Land of van der Waals, S. Neumayer, Center for Nanophase Materials pressure was 5 mTorr. Samples were grown with thicknesses ranging from Sciences, Oak Ridge National Laboratory; J. Brehm, Vanderbilt University; 5 – 50 nm, and with growth temperatures from room temperature to M.A. McGuire, Oak Ridge National Laboratory; M.A. Susner, Air Force 600°C, to determine optimum conditions. Structural characterization by x- Research Laboratory; E. Eliseev, National Academy of Sciences of Ukraine; ray diffraction demonstrates a high degree of epitaxy across a range of S. Jesse, S.V. Kalinin, Center for Nanophase Materials Sciences, Oak Ridge deposition temperatures and thicknesses. The deposition temperature and National Laboratory; A.N. Morozovska, National Academy of Sciences of thickness dependence of epitaxial quality is investigated, with a Ukraine; S. Pantelides, Vanderbilt University; N. Balke, Petro characterization of the strain state, mosaicity, and crystallographic Maksymovych, Center for Nanophase Materials Sciences, Oak Ridge relationship between substrate and film. Evidence for antiferromagnetic National Laboratory order forming domains in NiO is provided via magnetic characterization of Van der Waals crystals of metal thiophosphates can be thought of as the films. Our results are essential for the optimization of the fabrication of derivatives of transition metal dichalcogenides where 1/3 of metal atoms is high quality epitaxial antiferromagnetic films for practical spintronics replaced with diphosphorous, thereby stabilizing the remaining 2/3 of devices. metal ions in low oxidation states.1 Consequently, thiophosphates enable [1] J. Železný, P. Wadley, K. Olejník, A. Hoffmann, and H. Ohno, Nat. Phys. ultrathin magnetic, ferroelectric and Mott insulating materials, in q2D 14, 220 (2018) materials while also providing new opportunities for multifunctional [2] V. Baltz, A. Manchon, M. Tsoi, T. Moriyama, T. Ono, and Y. Tserkovnyak, interfaces .

Rev. Mod. Phys. 90, 015005 (2018). Of particular interest is CuInP2S6, where ferroelectricity emerges out of [3] R. Lebrun, A. Ross, S. A. Bender, A. Qaiumzadeh, L. Baldrati, J. Cramer, ionically conducting state .2,3 In this work, we discuss unusual and perhaps A. Brataas, R. A. Duine, and M. Kläui, Nature 561, 222 (2018). anomalous properties observed in CuInP2S6 in both states. 4 2 [4] S. Takei, B. I. Halperin, A. Yacoby, and Y. Tserkovnyak, Phys. Rev. B 90, CuInP2S6 exhibits giant negative electrostriction (Q33 = -3.2 m /C ), which 094408 (2014). leads to large piezoelectric coefficients despite small polarization values and increase of Tc with applied pressure. It's the only material other than [5] T. Moriyama, K. Oda, T. Ono, Sci. Rep. 8, 14167 (2018). polymer PVDF for which such behavior is experimentally confirmed. [6] L. Baldrati, A. Ross, T. Niizeki, C. Schneider, R. Ramos, J. Cramer, O. Density functional theory reveals that the reason for negative Gomonay, M. Filianina, T. Savchenko, D. Heinze, A. Kleibert, E. Saitoh, J. electrostriction is a slight movement of Cu ions into the van der Waals gap Sinova, and M. Kläui, Phys. Rev. B 98, 024422 (2018). due to anharmonicity of the potential well.4 Moreover, under high compressive strain, Cu starts to form interlayer bonds with sulfur across 10:00am TF+EM+MI+MN+OX+PS-MoM6 Structural and Magnetic the van der Waals gap, leading to an additional phase of high polarization. Properties of CoPd Alloys for Non-Volatile Memory Applications, S. Gupta, Consequently, the potential distribution exhibits 4 instead of the usual two J.B. Abugri, B.D. Clark, University of Alabama; P. Komninou, Aristotle minima - a quadruple well, that is precisely tunable by strain. In the University of Thessaloniki; Sujan Budhathoki, A.J. Hauser, P.B. Visscher, paraelectric state above ~70°C, Cu ion mobility drastically increases. University of Alabama Intriguingly, Cu can be reversibly extracted out of the lattice without visible A study of perpendicular magnetic anisotropy (PMA) CoPd alloys is damage. Finally, the selenide sibling CuInP2Se6, exhibits a lower transition presented as a simple means of pinning MgO-based perpendicular temperature and propensity toward antiferroelectric ordering under the magnetic tunnel junctions (pMTJs) for spin transfer torque magnetic tunnel effect of depolarizing fields. In this material, we have for the first time junction (STT-MRAM) applications. A compositional study of the CoxPd100-x observed piezoelectric response confined to domain walls (opposite to alloys at 50 nm thickness showed that the maximum coercivity and ferroelectrics), fulfilling the long-standing predictions for polar anisotropy was found for Co25Pd75. Perpendicular magnetic tunnel junction antiferroelectric domain walls and providing a new model system for stacks were deposited using different compositions of CoPd. Current-in- emergent properties of topological defects in ferroic order parameter plane tunneling measurements indicated that the TMR values roughly fields. correlated with the coercivity and anisotropy of the single layers. A thickness study indicated that the alloy was fully perpendicular for Research sponsored by Division of Materials Science and Engineering, Basic thicknesses as low as 20 nm. Various seed layers were employed to Energy Sciences, US Department of Energy. Microscopy was conducted at optimize the coercivity of the Co25Pd75 layer. Magnetometry, X-ray the Center for Nanophase Materials Sciences, which is a DOE Office of diffraction (XRD), scanning electron microscopy (SEM) and high resolution Science User Facility. transmission electron microscopy studies were carried out to relate the magnetic and structural properties of these layers. These studies showed that the highest coercivity Co25Pd75 was achieved on a seed layer of Ta/Pd 1Susner et al, Adv. Mater. 29,1602852 (2018) which helped to crystallize the CoPd layer in an fcc (111) orientation. 2Neumayer et al, Phys. Rev. Materials 3, 024401 (2019) 10:40am TF+EM+MI+MN+OX+PS-MoM8 Size Effects of the 3Balke et al, ACS Appl. Mater. Interfaces 10, 27188 (2018) Electromechanical Response in Ferroic Thin Films: Phase Transitions to 4 the Rescue, Nazanin Bassiri-Gharb, Georgia Institute of Technology Brehm et al, in review INVITED 11:40am TF+EM+MI+MN+OX+PS-MoM11 Adsorption-controlled Epitaxial Silicon-integrated ferroelectric thin films have been leveraged over the last Growth of the Hyperferroelectric Candidate LiZnSb on GaSb (111), D. Du, two decades for fabrication of high performance piezoelectric P. Strohbeen, University of Wisconsin - Madison; H. Paik, Cornell University; microelectromechanical systems (MEMS) devices. Ceramic Pb(ZrxTi1- C. Zhang, P. Voyles, Jason Kawasaki, University of Wisconsin - Madison x)O3(PZT) thin films have been often the material of choice, due to their A major challenge for ferroelectric devices is the depolarizing field, which large electromechanical response, especially at morphotropic phase competes with and often destroys long-range polar order in the limit of boundary compositions (MPB at x ~0.52), where co-existence of multiple ultrathin films. Recent theoretical predictions suggest a new class of crystallographic distortions can enhance extrinsic electromechanical materials, termed hyperferroelectics [1], should be immune to the contributions. However, ferroelectric thin films suffer from extrinsic size depolarizing field and enable ferroelectric devices down to the monolayer effects that lead to deteriorated piezoelectric properties in thin and ultra- limit. Here we demonstrate the epitaxial growth of hexagonal LiZnSb, one thin films. Here we report on different strategies for processing of thin of the hyperferroelectric candidate materials, on GaSb (111) substrates. films with enhanced piezoelectric response with respect to traditionally Due to the high volatility of all three atomic species, we find that processed PZT thin films. stoichiometric films can be grown in a thermodynamically adsorption- controlled window, using an excess zinc flux. Outstanding challenges

Monday Morning, October 21, 2019 5 8:20 AM Monday Morning, October 21, 2019 remain in controlling the point defects of LiZnSb and in controlling polytypism. While the films primarily grow in a hexagonal “stuffed wurtzite” phase (space group P63mc), which is has the desired polar structure, there exists a competing cubic “stuffed zincblende” polymorph that is nonopolar (F-43m). We will discuss our strategy towards controlling defects and polytypism in LiZnSb, which is based in large part on the wurtzite – zincblende polytypism observed in InAs. We will also present preliminary electrical measurements on phase pure ferroelectric capacitor structures. This work was supported by the Army Research office (W911NF-17-1-0254) and the National Science Foundation (DMR-1752797). [1] K. F. Garrity, K. M. Rabe, and D. Vanderbilt, Phys. Rev. Lett. 112, 127601(2014).

Monday Morning, October 21, 2019 6 8:20 AM Monday Afternoon, October 21, 2019 2D Materials surface is hydrogenated. The formation of C−H bonds determines new Room A226 - Session 2D+AP+EM+MI+MN+NS+PS+TF-MoA components in the C 1s core level spectrum that are attributed by DFT calculations to C atoms directly bonded to H and to their first neighbors. In Nanostructures including Heterostructures and Patterning parallel with chemisorption, with a much lower rate, H atoms intercalate of 2D Materials below Gr and bind to Ni surface sites. Thermal programmed desorption Moderator: Deep Jariwala, University of Pennsylvania measurements showed that chemisorbed hydrogen is released around 600 K, whereas the intercalated phase desorbs abruptly slightly below 400 K. 1:40pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA1 Tailoring and Patterning 2D Then the Gr cover, besides offering a storage volume for the intercalated H, Material Interfaces Through Chemical Functionalization, Arend van der stabilizes it above room temperature rising by a few tens of kelvins the H2 Zande, University of Illinois at Urbana-Champaign INVITED release temperature with respect to the bare Ni(111) surface. Two-dimensional materials are all surface, so any change in the surface chemistry affects the entire material. This offers a challenge and an opportunity to engineering the material properties and new device behavior. There are many strategies to altering the chemical structure of 2D materials, yet one of the most successful is the chemical The effectiveness of these results can be expanded by using Ni substrates functionalization with low energy plasmas such as hydrogen and fluorine. with large specific surface, as nanoparticles or nanostructured foils, which, when covered with Gr, might become media where hydrogen can be Functionalization enables phase changes within materials to dramatically alter their properties, can be applied post synthesis and device fabrication, loaded and stored above room temperature. and is compatible with lithography for spatial patterning. Most studies of chemical functionalization focus on single functionalization of single 2D materials, yet there are many opportunities when applying the principles of chemical functionalization to spatially engineer the properties though in [1] D. Lizzit et al. ACS Nano 13 (2019) 1828 plane interfaces or out of plane in heterostructures.

First, we will examine selective etching with XeF2 to pattern heterostructures using graphene etch stops. These techniques are self- limiting, yet scalable, and enable the patterning of 2D heterostructures into 2:40pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA4 Assembly of Arrays of 3D multilayer circuitry. Moreover, devices like encapsulated graphene Predefined Monolayer Features into vdW Heterostructure by a transistors fabricated with these techniques have exceptionally low contact Continuous Exfoliate-align-Release Process, Vu Nguyen, H. Taylor, resistances and mobilities which approach theoretical limits. University of California at Berkeley Second we will present a new strategy for tailoring the stoichiometry of One of the major challenges of van der Waals (vdW) integration of 2D functionalized graphene compounds through the systematic control of the materials is the high-yield and -throughput assembly of pre-defined ratio between adatoms. We demonstrate new ternary HFG compounds and sequence of monolayers into heterostructure arrays. Although a variety of reversible switching of material stoichiometry via the sequential exposure techniques have been developed to exfoliate the 2D materials from the source and deterministically place them onto a target substrate, they of graphene to low energy H plasma and XeF2 gas. By patterning regions of different functionalization on a single chip, we perform direct comparisons typically can transfer only either a wafer-scale blanket or a small flake at a and show spatially controlled tuning of the relative surface properties such time with uncontrolled size and shape. Here we present a method to as wettability, friction, electronic conductivity and molecular adhesion. exfoliate arrays of lithographically defined monolayer MoS2 and WS2 Taken together, these studies show that chemical functionalization offers features from multilayer sources and directly transfer them in a new atomically precise nanofabrication and materials engineering deterministic manner onto target substrates. The continuous exfoliate- techniques for scalable engineering of circuitry along all three dimensions. align-release process, without the need of an intermediate carrier substrate, was enabled by a new transfer medium fabricated by spin- 2:20pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA3 Dual-Route Hydrogenation coating a low-crosslinked and transparent adhesive on a transparent, of the Graphene/Ni Interface, Rosanna Larciprete, CNR-Institute for electrostatically active backing material with low surface energy. MoS2/WS2 Complex Systems, Roma, Italy; D. Lizzit, Elettra - Sincrotrone Trieste, vdW heterostructure arrays produced by this method were characterized, Trieste, Italy; M.I. Trioni, CNR-Institute of Molecular Science and showing coupled photoluminescence between the monolayers. Light- Technologies, Milano, Italy; P. Lacovig, L. Bignardi, S. Lizzit, Elettra - emitting devices using WS2 monolayer were also demonstrated, proving the Sincrotrone Trieste, Trieste, Italy; R. Martinazzo, Università degli Studi di functionality of the fabricated materials. This method promises to produce Milano, Milano, Italy large-area monolayer and multiplex heterostructure arrays with capability Although the high surface-to-weight ratio would make graphene (Gr) one to integrate with existing semiconductor manufacturing equipment. of the most promising material for hydrogen accumulation, up to now only 3:00pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA5 van der Waals moderate gravimetric density values of 1-2% have been obtained at room Heterojunction Photothermoelectric Effect in MoS2/Graphene temperature (RT). The ultimate H coverage is limited by the competition Monolayers, Yunqiu Kelly Luo, The Ohio State University; T. Zhou, between the adsorption and desorption/abstraction processes and by the University at Buffalo, State University of New York; M. Newburger, The elastic energy that accumulates in the C lattice once puckered by the local Ohio State Univesity; R. Bailey-Crandell, I. Lyalin, The Ohio State University; sp3rehybridization of the C atoms binding hydrogen. Moreover, for M. Neupane, U.S. Army Research Laboratory; A. Matos-Abiague, Wayne epitaxial Gr on metals, the substrate-induced Gr corrugation might State University; I. Zutic, University at Buffalo, State University of New York; modulates periodically H adsorption. In this respect, the Gr/Ni(111) R. Kawakami, The Ohio State University interface appears much more favorable than other graphene/metal systems, as the limitations due to the presence of the moirè supercell Two-dimensional (2D) van der Waals (vdW) heterostructures provide a vast vanish due to commensurate relation between the Gr and Ni(111) lattices. playground for exploring new phenomena due to its unique ability to tailor Moreover, hydrogenation might be favored by the peculiar reactivity of and combine dissimilar materials with atomic precision. In particular, the Gr/Ni(111).This issues motivated a re-investigation of the interaction of this combination of graphene and transition metal dichalcogenides (TMDC) particular interface with hydrogen. garners immense interest due to their novel optoelectronic, valleytronic and spintronic properties. Here, we report the observation of a highly tunable vdW heterojunction photothermoelectric effect (HPTE) in dual-

gated MoS2/graphene heterostructures, identified by a signature six-fold photocurrent pattern as a function of heterojunction bias and carrier In this study [1]we used x-ray photoelectron spectroscopy (XPS) and near density. In stark contrast to photovoltaic and photothermionic effects, we edge x-ray absorption fine structure spectroscopy (NEXAFS) to follow the discover a new mechanism arising from photoexcitation of hot electrons in RT hydrogenation of Gr/Ni(111) and determined the configuration of the graphene and subsequent thermoelectric transport across the vdW hydrogenated interface by scanning tunneling microscopy (STM). We found junction. While analogous to lateral photothermoelectric effects at quasi- that hydrogenation proceeds through a dual path that includes hydrogen 1D junctions in single layers, the vertical geometry of HPTE offers area chemisorption on top of the graphene followed by a slow but continuous scaling of 2D active regions and establishes, for the first time, the intercalation below graphene. At low coverage H atoms predominantly photothermoelectric response in vdW heterostructures. Operating at both adsorb as monomers and chemisorption saturates when ≈ 25% of the low (18 K) and room temperatures, the discovery of HPTE creates new

Monday Afternoon, October 21, 2019 7 1:40 PM Monday Afternoon, October 21, 2019 possibilities for electrically-tunable broadband photodetectors and 4:20pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA9 Structural Stability of atomically-thin spin caloritronic devices. Graphene Nanoflakes:From the View Point of Aromaticity, M. Ushirozako, H. Matsuyama, A. Akaishi, Jun Nakamura, The University of Electro- 3:20pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA6 Formation of Edge-bonded Communications (UEC-Tokyo), Japan MoS2-graphene Nanoribbons by On-surface Synthesis, Mark Haastrup, M. Recently, nano-scale graphene nanoflakes (GNFs) have attracted great Mammen, J. Rodríguez-Fernández, J.V. Lauritsen, Aarhus University, attention as one of the promising materials for electronics and spintronics. Denmark Kim et al. have successfully fabricated GNFs with various sizes up to 35 nm 2D materials exhibiting unique material properties have the potential for a and have reported that the photoluminescence property of GNFs depends huge impact on our future. Graphene, as the first discovered truly 2D on the size and the edge shape [1]. From the view point of the structural material, has been extensively studied. However, the lack of an intrinsic stability of GNFs, we have not yet acquired the systematic comprehension band gap makes it inadequate for electronic and optical devices. MoS2 from with regard to effects of shapes and sizes of GNFs on the stability. In the the family of transition metal dichalcogenides has been intensively present study, we have examined how the stability of GNFs is dominated investigated for its possibility to be used in future applications. The vision is by the edge shape and the size of GNFs, using first-principles calculations to integrate various 2D materials to realise an actual device. However, the within the density functional theory. actual assembly of these materials with high controllability remains a challenge. Vertical heterostructures, supported by Van der Waals In order to evaluate the stability of GNFs, we calculated the edge formation interactions, have already been realised by manually stacking 2D materials energy. First, we consider GNFs with the six-fold symmetry (D6h) and on top of each other[1]. An ultimate thin device can be realised by creating classify them into zigzag GNFs (ZZGNFs) and armchair GNFs (ACGNFs). lateral heterostructures with atomically sharp interfaces where each ACGNFs have two subtypes, AC(1) and AC(2), depending on whether material is directly bonded to another. Currently, methods for in-plane carbon atoms are just at the corner of the outermost envelope hexagon of GNFs. We define the edge purity as the ratio of the number of carbon bonding of MoS2 to other materials (e.g. graphene) are limited due to poor structural match. One possible solution is to develop selective bottom-up atoms at the edge unambiguously regarded as the armchair to the total methods for synthesis of molecular nanostructures by self-assembly. number of edge atoms. The purity of AC(1) is higher than that of AC(2). The 2 2 chemical formulae associated with ZZ, AC(1), and AC(2) are C6n H6n, C18n - This study aim to investigate the fundamental nature of bonding of 2 18n+6H12n-6, C18n -30n+12H12n-12, respectively. In addition, we also evaluate the graphene nanoribbons (GNRs) to the edges of MoS2 nanoparticles by structural stabilities of triangular and rhombus GNFs. scanning tunnelling microscopy (STM). The aim is to synthesise GNRs from precursor molecules through a thermally activated Ullmann reaction We calculated the edge formation energy of the GNFs having up to 1200 carbon atoms as a function of the number of edge carbon atoms [3]. The already used elsewhere[2,3]. After initial growth of MoS2, it is necessary to anneal in a hydrogen atmosphere to activate the edges to facilitate the formation energy of ZZGNFs is higher than that of ACGNFs irrespective of attachment of an intermediate structure of poly(para-phenylene) (PPP) the size of GNFs. This instability of ZZGNFs is attributed to the presence of wires. STM reveals the PPP wires have an affinity for the corners of the the so-called edge state. Indeed, it has also been shown that the formation energy of the zigzag graphene nanoribbon is higher than that of the MoS2 nanoparticles with a distance, obtained from line scans across the adsorption site, consistent with a covalent C-S bond. armchair one [4]. It is noted that AC(2) is slightly more stable than AC(1), whereas the purity of AC(2) is lower than that of AC(1). Such peculiar [1]: Pant et al., Nanoscale, 2016, 8, 7, 3870-3887 stabilization can be reasonably explained in terms of the aromaticity of [2]: Cai et al., Nature, 2010, 466, 7305, 470–473 GNFs. The Nucleus Independent Chemical Shifts (NICS) values, which is [3]: Basagni et al., J. Am. Chem. Soc., 2015, 137, 5, 1802-1808 averaged for the six-membered rings in GNFs, for AC(2) are lower than those for AC(1). This means AC(2) is more aromatic than AC(1). We will 4:00pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA8 The Effects of Metal- discuss the quantitative relationship between the stability and the modification and Two Dimensional (2D) Lamellar Structure on Catalytic aromaticity of GNFS. Performance of MFI Zeolite for Ethylene Conversion into Liquid [1] S. Kim et al., ACS Nano, 6, 9, 8203 (2012) Aromatics, Laleh Emdadi, L. Mahoney, D. Tran, I. Lee, US Army Research Laboratory [2] W. Hu et al., J. Chem. Phys. 141, 214704 (2014) The effects of two dimensional (2D) meso-/microporous structure and [3] A. Akaishi, M. Ushirozako, H.Matsuyama, andJ.Nakamura, metal modification with gallium or zinc on catalytic performances of Jpn.J.Appl.Phys. 57, 0102BA(2018) lamellar MFI zeolites in ethylene conversion reaction to liquid aromatics [4] S. Okada. Phys. Rev. B, 77, 041408 (2008) were investigated. Dual template technique was used to synthesize the 2D zeolite and metal modification of the zeolite was carried out by wet 4:40pm 2D+AP+EM+MI+MN+NS+PS+TF-MoA10 Wafer-scale 2D-3D Mixed impregnation method. The results of multiple analysis techniques such as Heterostructures Enabled by Remote Epitaxy through Graphene, Jeehwan TEM, XRD, Ar adsorption-desorption, UV-Visible spectroscopy, and H2-TPR Kim, Massachusetts Institute of Technology INVITED showed that the zeolite structure is a pivotal factor for controlling the type The current electronics industry has been completely dominated by Si- of metal dopant species forming on zeolite, their size, and their based devices due to its exceptionally low materials cost. However, distribution. Adding metal dopants to 2D zeolite structures improved the demand for non-Si electronics is becoming substantially high because yield of liquid aromatics and selectivity for mono-benzene alkylated current/next generation electronics requires novel functionalities that can aromatics compared to their microporous commercial MFI analogies while never be achieved by Si-based materials. Unfortunately, the extremely high decreased the coke formation rate. Zinc loaded lamellar MFI had the most cost of non-Si semiconductor materials prohibits the progress in this field. efficient catalytic performance among all studied catalysts with lowest Recently our team has invented a new crystalline growth concept, termed amount of total coke and highest fraction of light coke including mono- as “remote epitaxy”, which can copy/paste crystalline information of the benzene alkylated aromatics determined by combination of different wafer remotely through graphene, thus generating single-crystalline films techniques such as FTIR, UV-Vis, MS-temperature programmed oxidation on graphene [1,2]. These single-crystalline films are easily released from (TPO), FTIR-TPO, and GC-MS. This can be explained by higher accessibility the slippery graphene surface and the graphene-coated substrates can be of reactants to active sites and facilitated transport of products and coke infinitely reused to generate single-crystalline films. Thus, the remote precursors from lamellar structure of this zeolite and the lower epitaxy technique can cost-efficiently produce freestanding single- Brønsted/Lewis acid site ratio of this catalyst provided by metal crystalline films including III-V, III-N, and complex oxides. This allows modification which is more suitable for ethylene aromatization and unprecedented functionality of flexible device functionality required for suppresses the formation of heavy coke species. The catalytic performance current ubiquitous electronics. I will also present detailed mechanism of zeolite catalyst can be tuned by modulating both the textural and acidity behind remote atomic interaction through graphene [2]. In addition, we properties of the zeolite structure. The metal modified 2D lamellar MFI have recently demonstrated a manufacturing method to manipulate wafer- zeolites as bifunctional catalysts open an avenue for converting large scale 2D materials with atomic precision to form monolayer-by-monolayer reactant molecules to desired products by designing a catalyst with an stacks of wafer-scale 2D material heterostructures [3]. In this talk, I will optimal structure, acidity, and dispersion of metal dopants. discuss the implication of this new technology for revolutionary design of next generation electronic/photonic devices with combination of 3D/2D mixed heterostructures.

Monday Afternoon, October 21, 2019 8 1:40 PM Monday Afternoon, October 21, 2019 [1] Y. Kim, et al, and J. Kim, “Remote epitaxy through graphene enables within custom chambers and transmission electron microscopes where the two-dimensional material based layer transfer” Nature, Vol. 544, 340 ability to ‘see’ every atom in these atomically-thin crystals permits a unique (2017) opportunity to understand the forces governing their synthesis and [2] W. Kong, et al, and J. Kim, “Polarity govern atomic interaction through functionality. In situ optical spectroscopy techniques are described to two-dimensional materials”, Nature Materials, Vol. 17, 999 (2018) characterize the material’s evolving structure and properties, offering the opportunity to ‘close the loop’ between synthesis and optoelectronic [3] J. Shim, S. Bae, et al, and J. Kim, “Controlled crack propagation for functionality of 2D materials and heterostructures. atomic precision handling of wafer-scale two-dimensional materials” Science, 362, 665 (2018) Research sponsored by the U.S. Dept. of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Div. (synthesis science) and Scientific User Facilities Div. (characterization science). 2D Materials 3:00pm 2D+AP+EM+MI+NS+PS+TF-MoA5 Area-Selective Atomic Layer 1 Room A216 - Session 2D+AP+EM+MI+NS+PS+TF-MoA Deposition of 2D WS2 Nanolayers, Shashank Balasubramanyam , Eindhoven University of Technology, The Netherlands, Noord Brabant; 2D Materials Growth and Fabrication M.J.M. Merkx, Eindhoven University of Technology, The Netherlands; Moderator: Sarah Haigh, University of Manchester, UK W.M.M. Kessels, Eindhoven University of Technology, The Netherlands, 2:00pm 2D+AP+EM+MI+NS+PS+TF-MoA2 Synthesis of High Quality Netherlands; A.J.M. Mackus, Eindhoven University of Technology, The Monolayer Transition Metal Dichalcogenides using Direct Liquid Injection, Netherlands, Nederland; A.A. Bol, Eindhoven University of Technology, The Kathleen M. McCreary, E.D. Cobas, A.T. Hanbicki, M.R. Rosenberger, H.-J. Netherlands, Netherlands Chuang, B.T. Jonker, U.S. Naval Research Laboratory With continued downscaling of device dimensions, ultra-thin two dimensional (2D) semiconductors like WS2 are considered as promising In recent years, interest in monolayer transition metal dichalcogenides (TMDs) has rapidly increased, spurred by the possibility for integration into materials for future applications in nanoelectronics. At these nanoscale regimes, device fabrication with precise patterning of critical features is a variety of technologies such as photodetection, flexible electronics, and chemical sensing. While fundamental investigations can be performed on challenging using current top-down processing techniques. In this regard, exfoliated flakes or chemical vapor deposition synthesized isolated islands, area-selective atomic layer deposition (AS-ALD) has emerged as a promising candidate for bottom-up processing to address the complexities the limited size resulting from these techniques poses a significant barrier 1 2 forimplementation of TMDs in technological applications. To overcome of nanopatterning. Till date, AS-ALD of metals and dielectrics have been successfully demonstrated. However, AS-ALD of 2D materials has remained these obstacles, new synthesis avenues should be explored. Here, we elusive. In this contribution, we demonstrate area-selective deposition of outline a novel technique that utilizes a commercially available Anneal Sys growth chamber equipped with direct liquid injection (DLI) heads for all 2D WS2 nanolayers by using a three-step (ABC-type) plasma-enhanced ALD process. precursors. The use of liquid, rather than solid precursors, provides fine control of both metal and chalcogen precursors leading to the synthesis of AS-ALD of WS2 was achieved by using acetylacetone (Hacac) inhibitor (A), 2 monolayer MoS2 across cm areas. Photoluminescence, Raman, XPS, and bis(tertbutylimido)-bis(dimethylamido)-tungsten precursor (B), and H2S conductive AFM are used to evaluate DLI grown MoS2, and indicate high plasma (C) pulses. This process resulted in immediate growth on SiO2 while quality material having low defect density, with metrics comparable to or a significant nucleation delay was observed on Al2O3, as determined from better than exfoliated and chemical vapor deposition grown MoS2. in-situ spectroscopic ellipsometry (SE) and ex-situ X-ray photoelectron spectroscopy (XPS) measurements. The surface chemistry of this selective 2:20pm 2D+AP+EM+MI+NS+PS+TF-MoA3 Understanding and Controlling process was analysed by in-situ Fourier transform infrared spectroscopy the Growth of 2D Materials with Non-Equilibrium Methods and in situ (FTIR). The analyses revealed that the inhibitor adsorbed on the Al2O3 Diagnostics, David Geohegan, Y-C. Lin, Y. Yu, Oak Ridge National surface, blocking precursor adsorption, while little or no inhibitor Laboratory; C. Liu, G. Duscher, University of Tennessee Knoxville; A. adsorption was detected on the SiO2 surface where WS2 was readily Strasser, University of Texas at Dallas; A.A. Puretzky, Oak Ridge National deposited. Furthermore, the area-selective growth was demonstrated on Laboratory; K. Wang, Intel Corporation, USA; M. Yoon, C.M. Rouleau, Oak SiO2 samples with patterned Al2O3 on top. On SiO2, WS2 could be deposited Ridge National Laboratory; S. Canulescu, DTU Nanolab, Technical University with angstrom-level thickness control. of Denmark; P.D. Rack, University of Tennessee Knoxville; L. Liang, W. Zhang, H. Cai, Y. Gu, G. Eres, K. Xiao, Oak Ridge National Laboratory To improve the crystallinity, the AS-ALD WS2 films were annealed at temperatures within the thermal budget of industrial semiconductor INVITED processing (≤ 450°C). The annealed films exhibited sharp Raman peaks, Atomically-thin two-dimensional (2D) materials, including layered 2D which is a fingerprint of highly crystalline WS2. Furthermore, Raman line transition metal dichalcogenide (TMD) semiconductors and their scans over the patterns showed very sharp peak intensity transitions at the heterostructures, exhibit remarkable quantum properties that are SiO2-Al2O3 interface which confirmed that annealing had no impact on envisioned for energy-efficient photovoltaics, flexible optoelectronics, selectivity. catalysis, and quantum information science. However, significant synthesis and processing challenges currently limit the technologic development of To summarize, this work pioneered the combination of two key avenues in these “all-surface” materials, including wafer-scale, bottom-up synthesis of atomic-scale processing: area-selective growth and ALD of 2D materials. It uniform layers of crystalline 2D materials that are comparable in quality to is expected that the results of this work will lay the foundation for area- exfoliated flakes of bulk materials. As-synthesized crystals of 2D TMDs selective ALD of other 2D materials. display remarkable heterogeneity on both the atomistic level (e.g., 1 R. Chen and S.F. Bent, Adv. Mater. (2006). vacancies, dopants, and edge terminations) and on the mesoscopic length 2 A. Mameli, M.J.M. Merkx, B. Karasulu, F. Roozeboom, W.M.M. Kessels scale (e.g., misoriented grains, layer orientations, and interactions with and A.J.M. Mackus, ACS Nano (2017). substrates and adsorbates) that can strongly influence the structure and electronic properties in 2D materials. This heterogeneity offers a serious 3:20pm 2D+AP+EM+MI+NS+PS+TF-MoA6 Growth Behavior of Hexagonal challenge for synthesis and processing, yet offers a tremendous Boron Nitride on Cu-Ni Binary Alloys, Karthik Sridhara, Texas A&M opportunity to tailor functionality. University; J.A. Wollmershauser, U.S. Naval Research Laboratory; L.O. Here we describe several approaches that are being developed for in situ Nyakiti, Texas A&M University; B.N. Feigelson, U.S. Naval Research diagnostic analysis and control of synthesis and heterogeneity. In addition Laboratory to conventional vapor transport techniques, progress in laser-based Controlled growth of large area n-layered chemical vapor deposited (CVD) approaches for 2D synthesis and modification, such as pulsed laser hexagonal boron nitride (h-BN) is of great interest as a tunnel dielectric, deposition (PLD) and pulsed laser conversion of precursors, are presented and substrate for graphene and transition metal dichalcogenides (TMDs). that permit control of the growth environment using time-resolved in situ The CVD growth of h-BN has been demonstrated on various transition diagnostics. The non-equilibrium advantages of PLD to form alloys and metal catalytic substrates such as Cu, Ni, Pt and Fe. Of these metal vertical heterojunctions are demonstrated using the tunable kinetic energy substrates, Cu and Ni are frequently used due to their relative abundance and digital nature of the process. Correlated atomic-resolution electron and low cost. However, h-BN growth on Cu leads to monolayer films, and microscopy and atomistic theory are used to understand the size and growth on Ni yields thicker, substrate grain-dependent films. Therefore, a stoichiometry of the “building blocks” deposited for synthesis and the forces that guide assembly. 2D crystals are grown directly on TEM grids 1 TFD James Harper Award Finalist Monday Afternoon, October 21, 2019 9 1:40 PM Monday Afternoon, October 21, 2019 cost-effective transition metal substrate is needed that will facilitate demonstrate layer-by-layer growth of BN on B2O3/Si with an average controlled n-layered h-BN growth. growth rate of ~1.4 Å/cycle, accompanied by some B2O3 removal during the In this work, we prepare isomorphous Cu-Ni binary alloys from 10-90 wt.% first BN cycle. In contrast, continuous BN growth was observed on B-Si- Ni by creating Ni-rich (Ni-Cu) and Cu-rich (Cu-Ni) alloys using electroplating oxide without any reaction with the substrate. XPS data also indicate that of Cu on Ni foils and Ni on Cu foils, respectively. The electroplated foils are the oxide/nitride heterostructures are stable upon annealing in ultrahigh then annealed at ~1030° C for >5 hours to create Ni-Cu and Cu-Ni alloys. vacuum to >1000 K. XPS data, after the exposure of these heterostructures The alloys are subsequently polished mechanically to create a planarized to ambient, indicate a small amount of BN oxidation at the surface NH surface suitable for h-BN growth. The surface morphology before and after species, with no observable hydroxylation of the underlying oxide films. polishing is assessed using a scanning electron microscope (SEM). Energy These results demonstrate that BN films, as thin as 13 Å, are potential dispersive spectroscopy (EDS) characterization of the alloys confirms a candidates for passivating boron oxide films prepared for shallow doping designed stoichiometry at every weight percent. h-BN is grown on the applications. alloys using atmospheric pressure chemical vapor deposition (APCVD) at 5:00pm 2D+AP+EM+MI+NS+PS+TF-MoA11 Atomic Layer Deposition of 1030° C, with ammonia borane as the precursor, and H2/N2 as the carrier SiO2 on Group VIII Metals: Towards Formation of a 2D Dielectric, T. Suh, R. gas flowing at ~200 sccm. Cu and Ni foils are used as control samples for Yalisove, James Engstrom, Cornell University this study. Fourier transform infrared reflection absorption spectroscopy The atomic layer deposition (ALD) of many metals, particularly Group VIII (FT-IRRAS) is used to confirm and characterize h-BN growth directly on Cu, (now known as Groups 8, 9 and 10), on SiO2 has been an active area of Ni and alloy substrates. SEM is performed to evaluate the h-BN film and research in many fields, which include microelectronics and heterogeneous crystal morphology. The results indicate that the h-BN growth behavior on catalysis. There have been many fewer studies of the inverse—the Ni-Cu is different than on Cu-Ni alloys. A trend of decreasing h-BN amount deposition of SiO2 on many of these same metals. One possible reason to with reducing Ni concentration is observed on Ni-Cu alloys while no such explore the ALD growth of SiO2 on transition metals is that it might provide trend is observed on Cu-Ni alloys. Additionally, there are large (~20 µm) a route to an atomically thick SiO2 dielectric, silicatene. Silicatene is a 2D multilayer and monolayer single crystals of h-BN on Ni-Cu alloys, and material that consists of a bilayer of Si2O3 linked to each other by bridging predominantly monolayer crystals and films of h-BN on Cu-Ni alloys. The oxygen atoms (giving SiO2), where there are no dangling bonds or covalent difference in growth behavior is studied using x-ray photoelectron bonds to the underlying substrate on which it is grown. For example, an spectroscopy (XPS) and electron backscattering diffraction (EBSD), which established route to form silicatene involves deposition of elemental Si in reveal that the alloy surface composition determines the h-BN growth. This UHV and subsequent high-temperature annealing on various single- work demonstrates how Cu-Ni alloy substrate of different compositions, crystalline metal surfaces including, but not limited to, Ru(0001), Pt(111), along with CVD growth conditions, can be used to control h-BN growth. and Pd(100). Such a process, unfortunately, is likely not compatible with 4:20pm 2D+AP+EM+MI+NS+PS+TF-MoA9 Controlled Growth of Transition high-volume manufacturing. With this motivation we embarked on a study Metal Dichalcogenide Monolayers for Applications in Nanoelectronic and of the plasma-assisted ALD of SiO2 on e-beam deposited polycrystalline thin Nanophotonic Devices, A. George, C. Neumann, D. Kaiser, R. Mupparapu, films of Ru, Pt and Pd using a commercial ALD reactor. We analyzed both Friedrich Schiller University Jena, Germany; U. Hübner, Leibniz Institute of the thin films and the starting substrates using a combination of techniques Photonic Technology, Jena, Germany; Z. Tang, A. Winter, I. Staude, Andrey including contact angle, spectroscopic ellipsometry (SE) and X-ray Turchanin, Friedrich Schiller University Jena, Germany photoelectron spectroscopy. Thin films of SiO2 were deposited using Controlling the flow rate of precursors is highly essential for the growth of tris(dimethylamido)silane and an oxygen plasma at a substrate high quality monolayer crystals of transition metal dichalcogenides (TMDs) temperature of 200 °C, and we examined growth for 5, 10, 20, 50 and 100 by chemical vapor deposition. Thus, introduction of an excess quantity of cycles. Contact angle measurements showed immediate evidence for SiO2 precursors affects the reproducibility of the growth process and results in deposition on all metal surfaces, and the contact angle decreased and the multilayer growth. Here, we demonstrate the use of Knudsen-type remained constant and < 10° from 5 to 100 cycles of ALD. From SE we effusion cells for controlled delivery of sulfur precursor for the large area, found little evidence of an incubation period, and growth was linear for the high density, size-controlled and highly reproducible growth of monolayer range of sample examined and the thickness deposited per cycle was -1 TMD crystals [1]. The size of the grown crystals can be tuned between 10 - remarkably constant at a value of 0.76-0.78 Å-cycle . Analysis of these films using angle-resolved XPS was consistent with the formation of a thin 200 µm. We grow MoS2, WS2, MoSe2 and WSe2 monolayer crystals as well film of SiO2 with uniform thickness. Having characterized the thin film as MoSe2-WSe2 lateral heterostructures and characterize them by optical microscopy, atomic force microscopy, Raman spectroscopy, thickness-ALD cycle relationship we subjected SiO2 thin films with thickness photoluminescence spectroscopy and electrical transport measurements. It of ~ 7-15 Å to post-deposition high-temperature anneals in oxygen furnace. has been found that they possess a high crystalline, optical and electrical Initial attempts to form silicatene with an anneal at 800 °C, produced a quality based on their single crystalline nature. We demonstrate their structure suggesting possible interfacial reaction between the SiO2 and Ru, implementation in novel field-effect and nanophotonic devices and perhaps involving silicide formation. We will end our presentation with a discusse an influence of the point defect density on their functional discussion of recent work involving a more extensive examination of the characteristics [2-3]. Moreover, we present a novel synthetic route for the post-deposition annealing step, and deposition on patterned wafers. integration of TMDs into lateral heterostructures with other 2D materials [4]. [1] A. George et al., J. Phys.: Mater. 2 (2019) 016001. [2] T. Bucher et al., ACS Photonics 6 (2019) 1002. [3] R. Meyer et al., ACS Photonics 6 (2019) DOI: 10.1021/acsphotonics.8b01716 [4] A. Winter et al., Carbon 128 (2018)106. 4:40pm 2D+AP+EM+MI+NS+PS+TF-MoA10 Atomic Layer Deposition of BN as a Novel Capping Barrier for B2O3, Aparna Pilli, J. Jones, J.A. Kelber, University of North Texas; A. LaVoie, F. Pasquale, Lam Research Corporation

The deposition of boron oxide (B2O3) films on Si and SiO2 substrates by atomic layer deposition (ALD) is of growing interest in microelectronics for shallow doping of high aspect ratio transistor structures. B2O3, however, forms volatile boric acid (H3BO3) upon ambient exposure, requiring a passivation barrier, for which BN was investigated as a possible candidate. Here, we demonstrate, deposition of BN by sequential BCl /NH reactions at 600 K on two different oxidized boron substrates: (a) B O deposited using BCl /H O ALD on Si at 300 K (“B O /Si”); and (b) a boron-silicon oxide formed by sequential BCl /O reactions at 650 K on SiO followed by annealing to 1000 K (“B-Si-oxide”). X-ray photoelectron spectroscopy (XPS) data

Monday Afternoon, October 21, 2019 10 1:40 PM Tuesday Morning, October 22, 2019 2D Materials shown that protruding defects prevent the realisation of pristine interfaces Room A216 - Session 2D+AS+MI+NS-TuM between transition metal selenides (MoSe2, WSe2, NbSe2) and boron nitride, unless exfoliation is performed in an inert environment.[2] 2D Materials Characterization including Microscopy and We have analysed microstructures produced when 2D van der Waals Spectroscopy materials (graphite, boron nitride, MoSe2) are subjected to mechanical Moderator: David Geohegan, Oak Ridge National Laboratory deformation and find that the types of defect can be predicted from just the bend angle and thickness of the materials.[3] In particular we find that 8:00am 2D+AS+MI+NS-TuM1 Near-field Infrared Spectroscopy of Single above a critical thickness the materials exhibit numerous twin boundaries Layer MnPS3, Sabine Neal, University of Tennessee Knoxville; H-S. Kim, and for large bend angles these can contain nanoscale regions of local Rutgers University; K.A. Smith, A.V. Haglund, D.G. Mandrus, University of delamination. Such features are proposed to be important in determining Tennessee Knoxville; H.A. Bechtel, Advanced Light Source, Lawrence how easily the material can be thinned by mechanical or liquid Berkeley National Laboratory; G.L. Carr, National Synchrtoron Light Source exfoliation.[3] II, Brookhaven National Lab; K. Haule, D. Vanderbilt, Rutgers University; J.L. Musfeldt, University of Tennessee Knoxville 2D material heterostructures are also enabling new STEM imaging In order to explore the properties of a complex van der Waals material capabilities. We show they can be used as a platform to study real time under confinement, we measured the near-field infrared response of the reactions in liquid environments with unprecedented spatial resolution and spectroscopic capabilities [4]. We further demonstrate that graphene magnetic chalcogenide MnPS3 in bulk, few-, and single-layer form and compared the results with traditional far field vibrational spectroscopy and encapsulation allows imaging of point defect dynamics, structural degradation and mechanically induced stacking faults in 2D complementary lattice dynamics calculations. Trends in the activated Bu mode near 450 cm-1 are particularly striking, with the disappearance of this monochalcogenides, GaSe and InSe [1]. structure in the thinnest sheets. Combined with the amplified response of References the Ag mode and analysis of the Au + Bu features, we find that the symmetry [1] D G Hopkinson et al, ACS Nano, (2019) 10.1021/acsnano.8b08253 is unexpectedly increased in single-sheet MnPS3. The monoclinicity of this [2] A P Rooney et al. Nano Letters, (2017) 17, 5222. system is therefore a consequence of the long-range stacking pattern rather than local structure. [3] A P Rooney et al. Nature Communications (2018) 9, 3597 [4] D J Kelly et al Nano Letters, (2018) 18, 2, 1168 8:20am 2D+AS+MI+NS-TuM2 Multi-parameter Analysis of Genesis and Evolution of Secondary Electrons produced in the Low Energy Regime, 9:20am 2D+AS+MI+NS-TuM5 Low-Energy Electron Induced Disordering Alessandra Bellissimo, ETH Zürich, Switzerland; G.M. Pierantozzi, CNR - and Decomposition of Self-assembled Monolayers on Au(111), Jodi Istituto Officine Materiali, Italy; A. Ruocco, G. Stefani, Università degli Studi Grzeskowiak 1 , University at Albany - SUNY; C.A. Ventrice, Jr., SUNY Roma Tre, Italy; O. Ridzel, V. Astašauskas, W.S.M. Werner, Technische Polytechnic Institute Universität Wien, Austria; M. Taborelli, CERN, Switzerland; G. Bertolini, U. To study the interaction of low energy electrons with thin organic films, Ramsperger, ETH Zürich, Switzerland; O. Gürlü, ETH Zürich, Switzerland, measurements have been performed on electron induced disordering and Turkey; D. Pescia, ETH Zürich, Switzerland decomposition of 1-decanethiol molecules grown via vapor phase The mechanisms responsible for electron-induced Secondary Electron deposition on Au(111). Surface analysis techniques were used to Emission (SEE) generation of these ubiquitous Secondary Electrons (SEs) in characterize the monolayers before and after electron exposure. LEED was a solid surface is not yet fully understood. In particular, the question how used to determine the structure of the SAM and the rate of disordering and many “true secondary” electrons are generated and emitted from the decomposition. It was observed that the diffraction pattern of the lying target per incident primary electron awaits resolution and is of great down phase of the SAM, held near 100 K, almost completely disappears fundamental as well as technological importance. The present work reports within about three minutes of exposure. However, when the temperature on a study of these and related questions by means of a variety of of the irradiated sample was raised to 300 K and then cooled back down to spectroscopic tools of increasing finesse. The interaction of Low-Energy around 100 K, most of the intensity of the diffraction pattern returns, Electrons with surfaces exhibiting different long-range order, was indicating that electron exposure is primarily inducing disorder. TPD was investigated by combining measurements of the Total Electron Yield in used to evaluate the thermal stability of the SAMs and the resulting absolute units, single-electron as well as (e,2e)-coincidence spectroscopy. desorption products after electron exposure. For the standing up phase This investigation has led to the disentanglement of the elementary SAM, two desorption features for the hydrocarbon fragments of the SAM processes that need to be considered and comprehended for the are observed, one around 130 °C and a second near 220 °C. For the lying understanding of the SE-generation probability, fully taking into account down phase, only the higher temperature desorption feature is observed, both energy and momentum conservation in the collision and the band which indicates that the SAM is converting from the standing up phase to structure of the solid. Single ionising scattering events, assisted by the lying down phase during the heating process. For both phases, collective excitations, i.e. plasmons, constitute one of the fundamental desorption peaks for S and H2S at around 250 °C were observed, suggesting ingredients leading to SEE. In the Low-Energy-regime the electron yield of a that there is a high probability for the alkane chain of the decanethiol material is constituted by the interplay of reflectivity and SEE, both strongly molecule to detach from the sulfur head group. After electron exposure of dictated by the target band structure. The gathered information is further the standing up phase, a large reduction in the intensity of the two used in an attempt to interpret the signal generation mechanisms relevant desorption peaks for the masses monitored for the hydrocarbon fragments in Scanning Field-Emission Microscopy (SFEM) [1]. was observed. However, the intensities of the peaks associated with S and Reference: H2S were similar to those for the samples that were not irradiated with electrons. For the lying down phase, the intensities and positions of all of [1] A. Bellissimo, PhD Thesis, "Multiparameter Analysis of Genesis and the desorption peaks were similar to the unexposed SAMs, which indicates Evolution of Secondary Electrons produced in the Low Energy Regime", URL: that the cross-section for electron beam damage for the lying down phase https://www.researchgate.net/publication/332684398_Multiparameter_A is much lower than that for the standing up phase. Ex-situ XPS was used to nalysis_of_Genesis_and_Evolution_of_Secondary_Electrons_produced_in_ monitor the decomposition of the SAMs. After irradiation with 80 eV the_Low_Energy_regime electrons, an uptake of oxygen was observed in the XPS measurements for 8:40am 2D+AS+MI+NS-TuM3 Probing Point Defects, Folds and Interfaces both samples. This oxygen uptake gives evidence that oxygen in the air is reacting with carbon and sulfur atoms whose bonds were broken during in 2D Material Heterostructures using Scanning Transmission Electron electron exposure. Microscopy, Sarah Haigh, University of Manchester, UK INVITED Scanning Transmission Electron Microscopy (STEM) is one of the few 9:40am 2D+AS+MI+NS-TuM6 Continuous Silicene, Silicene Ribbons and techniques able to probe the structure and chemistry of 2D materials when Surface Reconstructions on h-MoSi2, Anna Costine, C. Volders, University these are stacked to form vertical heterostructures. By combining STEM of Virginia; M. Fu, Oak Ridge National Laboratory; P. Reinke, University of with electron energy loss spectroscopy and energy dispersive X-ray Virginia spectroscopy it is possible to characterise individual point defects,[1] to Silicene has emerged as a 2D material of interest because of its spin -orbit measure interlayer distances for dissimilar materials [2] and to investigate coupling, tunable electronic structure, and Dirac type behavior. Synthesis the microstructure of mechanically deformed structures at the atomic scale of silicene with preserved Dirac-type electronic structure has proven [3]. We have extensively employed plan view and cross sectional STEM imaging to investigate complex 2D heterostructures. For example, we have 1 ASSD Student Award Finalist Tuesday Morning, October 22, 2019 11 8:00 AM Tuesday Morning, October 22, 2019 challenging, but is critical to realizing theoretically predicted quantum Microscopy (LEEM) added further insight into the lateral extension of the states and devices. To date, Ag(111) remains the most popular substrate SLs and the structural order at the atomic level. for silicene synthesis, but is discussed controversially due to its similarity [1] H. Bana, E. Travaglia, L. Bignardi, P. Lacovig, C. E. Sanders, M. Dendzik, with surface alloys. Silicene has also been synthesized on other substrates M. Michiardi, M. Bianchi, D. Lizzit, F. Presel, D. D. Angelis, N. Apostol, P. K. including Ir, IrSi3, and ZrB2. Silicene synthesis on a semiconducting substrate Das, J. Fujii, I. Vobornik, R. Larciprete, A. Baraldi, P. Hofmann and S. Lizzit, with a low buckling conformation to conserve the Dirac-type behavior 2D Materials, 2018, 5, 035012. would be ideal. The synthesis of silicene on new substrates that allow for direct device integration is an important next step. [2] L. Bignardi, D. Lizzit, H. Bana, E. Travaglia, P. Lacovig, C. E. Sanders, M. Dendzik, M. Michiardi, M. Bianchi, M. Ewert, L. Buss, J. Falta, J. I. Flege, A. We developed an alternate approach to silicene synthesis that allows for Baraldi, R. Larciprete, P. Hofmann, and S. Lizzit, Physical Review Materials silicene synthesis on semiconducting silicides. The (0001) surface of h- 3, 014003 (2019). MoSi2 has hexagonal symmetry and a lattice constant close to that of silicene. Our recent measurements support the assumption that silicene is 11:20am 2D+AS+MI+NS-TuM11 Surface Reactivity of MoS2 by ambient electronically decoupled from the substrate. The h-MoSi2 crystallites, pressure X-ray Photoelectron Spectroscopy, Rafik Addou, D. Dardzinsky, which are terminated by the (0001) plane are grown by depositing Mo onto G.S. Herman, Oregon State University a Si (001) or Si(111) surface. Upon annealing to ~800℃, the Si atoms Molybdenum disulfide (MoS2) has potential applications as a low-cost decouple from the underlying surface and form a weakly buckled silicene catalyst for the hydrogen evolution reaction (HER). Defect sites in MoS2 layer with the √3 x√3 surface as seen by STM. have been demonstrated to have high catalytic activities, where edge sites Our recent work expands this study and uses STM/S at 77 K to achieve a and sulfur vacancies are the major active sites for HER. Intentionally comprehensive description of silicene-on-silicide. The amount of Mo inducing defects offers a simple way to enhance the reactivity of MoS2 and deposited (0.3 nm - 18 nm) and annealing temperature (700- 1000℃) were other 2D materials. In this study, we have characterized the surface varied. All surface structures discussed here are on h-MoSi2 crystallites in reactivity and the catalytic activities of bulk MoS2 samples using ambient the (0001) plane,. Three distinct surface structures coexist - silicene ribbons pressure X-ray photoelectron spectroscopy (APXPS). The pristine surface , a 4x4 reconstruction, and a complex reconstruction which is very sensitive was exposed to 1 mbar of H2O vapor for temperatures ranging from 300 to to variations in the bias voltage. The electronic structure of silicene-ribbons 573 K. APXPS Mo 3d, S 2p, and O 1s core levels do not show any significant shows a V-shaped density of states close to EF, indicative of Dirac-like changes under these reaction conditions due to the inert nature of the behavior, while the other reconstructions are semiconducting. The surface MoS2 surface. To activate the MoS2 basal plane to improve surface reactivity, we have formed well-controlled densities of defects using Ar+ and electronic structures observed on h-MoSi2 crystallites as a function of the synthesis conditions will be discussed. The preference for silicene- sputtering. The defective surfaces were exposed to 1 mbar of H2O vapor for ribbons in the low T STM/STS measurements is currently attributed to a temperatures ranging from 300 to 600 K. Changes in the APXPS Mo 3d, S faster post-deposition cooling rate, but the exact mechanism is still open to 2p, and O 1s core levels indicate that the surface is much more reactive to debate. We will present a detailed discussion of the electronic structure of H2O, with the formation of Mo-O bonds. These results are consistent with silicene and silicene ribbons, and suggest mechanisms for the transition the reduction in the H2O gas phase which was measured by operando mass from the (0001) surface to silicene. Our goal is to develop synthesis spectrometry. We have found that the reactivity strongly depends on the approaches suitable for device integration of both silicene conformations. temperature and the size and density of defects. Following this first report of APXPS on MoS2 acquired at more realistic pressure, we will also report 11:00am 2D+AS+MI+NS-TuM10 Epitaxial Growth and Characterization of the HER activity and X-ray absorption spectroscopy (XAS) on the pristine Single-Orientation Single-Layer Transition Metal Dichalcogenides on surface and compare it with defective surfaces. Our findings demonstrate Au(111), L. Bignardi, University of Trieste, Italy; Daniel Lizzit, Elettra - that the reactivity and the catalytic activity of MoS2 are significantly Sincrotrone Trieste, Trieste, Italy; B. Harsh, E. Travaglia, Department of improved through the formation of defects. Physics, University of Trieste, Italy; C.E. Sanders, iNANO, Aarhus University, Denmark, UK; M. Dendzik, Aarhus University, Denmark, Germany; P. 11:40am 2D+AS+MI+NS-TuM12 Surface Characterization of 2D Materials Lacovig, Elettra-Sincrotrone Trieste, Italy; M. Michiardi, iNANO, Aarhus and their 3D Analogues using XPS, Jonathan Counsell, S.J. Coultas, C.J. University, Denmark, Canada; M. Bianchi, Aarhus University, Denmark; R. Blomfield, N. Gerrard, Kratos Analytical Limited, UK; C. Moffitt, Kratos Larciprete, CNR-Institute for Complex Systems, Roma, Italy; J.I. Flege, J. Analytical Limited; A.J. Roberts, Kratos Analytical Limited, UK Falta, University of Bremen, Germany; P.K. Das, Abdus Salam International Since the synthesis of Graphene in 2004 there has been significant interest Centre for Theoretical Physics, Trieste, Italy; J. Fujii, I. Vobornik, IOM-CNR, in novel 2D materials. Indeed this area has produced an abundance of high Laboratorio TASC, Trieste, Italy; M. Ewert, L. Buß, University of Bremen, impact publications and so far >$10bn has been committed globally to both Germany; A. Baraldi, University of Trieste, Italy; P. Hofmann, Aarhus fundamental research and commercialisation. This interest has been due to University, Denmark; S. Lizzit, Elettra - Sincrotrone Trieste, Trieste, Italy the unique properties exhibited such as mechanical strength and It has been widely demonstrated that Transition Metal Dichalcogenides charge/heat transfer. The potential commercial possibilities are diverse with applications as varied as heat management and dissipation to (TMDs), and in particular MoS2 and WS2 could be good candidates for future electronic devices because of their intrinsic electronic properties increasing computer processing power. To fully understand the nature and and their potential for ultimate device scaling. In the single layer (SL) form, potential of these materials a comprehensive surface characterisation is the inversion symmetry breaking and the strong spin-orbit coupling of the necessary. heavy transition metals (Mo or W) open new possibilities for data storage Herein we illustrate how by applying conventional surface analysis and computing thanks to the spin and valley degrees of freedom. However, techniques with novel methodologies it is possible to create a more in order to investigate the fundamental physics behind these materials and complete picture of the chemical and physical nature of deposited 2D to produce high quality electronic devices, SL TMDs with enough large area materials. Both organic and inorganic 2D materials will be explored to and high quality are demanded. In particular, single domain oriented demonstrate the methods and capabilities. Dichalcogenide materials layers, that are SLs without mirror domains, allow to strongly suppress (sulphides and selenides) containing different metal centres were analysed defects due to the absence of grain boundaries which are known to with XPS, and angular resolved methods, to calculate layer thicknesses, degrade the overall performances. stoichiometry and chemical states. The lateral distribution of CVD ultra-thin We here present a successful synthesis method based on physical vapor films was studied using both macro and micro area XPS imaging modes to distinguish uniformity and evenness. The application of UPS will explore deposition that consists in dosing W or Mo in H2S atmosphere onto Au(111), and provide an in-depth characterization of the synthesized SL the bonding structure, sensitivity of the materials and as a potential tool TMDs through different surface science techniques. Synchrotron radiation for identifying damage/defects in the surface lattice. The merits and pitfalls based photoelectron spectroscopy in the fast modality (fast-XPS) was used of ion etching will be discussed and a complete method and protocol will to carefully tune the growth parameters whereas high resolution (HR-XPS) be proposed for limiting spectral artefacts and therefore misleading results. was used for the characterization. In particular fast-XPS allowed to The effects of deposition and analysis on the 2D materials’ structure and composition will be highlighted as will the characterisation of unwanted optimize the growth parameters which turned out to be different for MoS2 reduction/oxidation, contamination and structural defects. Utilising the [1] with respect to WS2[2]. Then, photoelectron diffraction (XPD) was employed to find the structural parameters of the SLs and to complete surface analysis tool box allows the analyst to gain further insight unambiguously determine their single orientation character and the and to fully understand the complex nature of these novel materials. relative alignment with respect to the underlying substrate. Scanning Tunneling Microscopy (STM), Low Energy Electron Diffraction (LEED) and Tuesday Morning, October 22, 2019 12 8:00 AM Tuesday Morning, October 22, 2019 12:00pm 2D+AS+MI+NS-TuM13 Characterization of Catalytic Active Sites by circularly polarized light. Ab initio calculations provide an explanation of on the Surface of MoS2 2-D Materials, Miguel Jose Yacaman, University of this unique and potentially useful property and indicate that it is a result of Texas at San Antonio; T. Zepeda, S. Fuentes Moyado, CNyN UNAM the indirect character of both electronictransitions. These peaks are Ensenada, Mexico doubleindirect excitons. i.e.indirect in both real and reciprocal space, split Materials such as the MoS2 have been used in catalysis at industrial level by relativistic effects. for many decades mostly on the hydrodesulfurization of naftas. This research was performed while H.-J.C. held an American Society for However more stringent regulations about the sulfur amount in diesel has Engineering Education fellowship and M.R.R and S.V.S held a National printed the need to improve the catalysts .In order to achieve that it is Research Council fellowship at NRL. This work was supported by core important to understand the nature of the active sites and ways to improve programs at NRL and the NRL Nanoscience Institute. This work was also the activity.In this presentation we discuss the use of in-situ techniques to supported in part by a grant of computer time from the DoD High study the surfaces of MoS2 materials made of few layers and discuss the Performance Computing Modernization Program at the U.S. Army Research role of the sites on the crystal edges.We also demonstrate that during the Laboratory Supercomputing Resource Center. reaction the MoS2 material becomes crumpled and changes from 9:20am 2D+EM+MI+MN+NS+QS-TuM5 Integrating 2D Magnet 1T-MnSe2 semiconductor to metallic. with Topological Insulator Bi2Se3, Tiancong Zhu, The Ohio State University; D. O'Hara, University of California, Riverside; J.J. Repicky, S. Yu, M. Zhu, B.A. Noesges, T. Liu, M. Brenner, L.J. Brillson, J. Hwang, F.Y. Yang, J.A. Gupta, R. 2D Materials Kawakami, The Ohio State University Room A226 - Session 2D+EM+MI+MN+NS+QS-TuM Integrating two-dimensional(2D) magnet with topological insulator is an Novel Quantum Phenomena exciting topic. Other than the possible proximity induced magnetic ordering inside topological insulator, the 2D magnet/ topological insulator Moderator: Arend van der Zande, University of Illinois at Urbana- heterostructure can also lead to more efficient spin orbit torque switching, Champaign or the formation of magnetic skyrmions. The recent discovery of room 8:00am 2D+EM+MI+MN+NS+QS-TuM1 Charge Density-Wave States in temperature ferromagnetic ordering in 2D material MnSe and VSe further Single-Layer Transition-Metal Dichalcogenides, Phil King, University of St brings more potential in such heterostructure systems. In this talk, we Andrews, UK INVITED report the synthesis and characterization of 2D magnet 1T-MnSe on Control over materials thickness down to the single-atom scale has topological insulator Bi Se . Monolayer of MnSe is grown on Bi Se with emerged as a powerful tuning parameter for manipulating not only the molecular beam epitaxy, and subsequently characterized with various single-particle band structures of solids, but increasingly also their techniques, including X-ray diffractometry (XRD), X-ray photoemission interacting electronic states and phases. A particularly attractive materials spectroscopy (XPS) and scanning tunneling microscopy (STM). STM system in which to explore this is the transition-metal dichalcogenides, measurement reveals the co-existence of monolayer a-MnSe(111) and 1T- both because of their naturally-layered van der Waals structures as well as MnSe2 on Bi2Se3 surface. By performing spin-polarized STM measurement the wide variety of materials properties which they are known to host. Yet, with Cr tip, we observed directly the magnetic signal from 1T-MnSe2 on how their interacting electronic states and phases evolve when thinned to Bi2Se3. The growth of 1T-MnSe2 on Bi2Se3 further leads to the MBE the single-layer limit remains a key open question in many such systems. synthesis of magnetic topological insulator Bi2MnSe4, which also shows Here, we use angle-resolved photoemission to investigate the electronic ferromagnetism down to the monolayer limit. The structural and magnetic structure and charge density wave (CDW) phases of monolayer TiSe2, TiTe2, characterization of the material will also be discussed in this talk. and VSe2. Three-dimensionality is a core feature of the electronic structure 9:40am 2D+EM+MI+MN+NS+QS-TuM6 Effect of Exchange-correlation of all of these parent compounds, but we show how their CDW phases not Functional and Structural Constraints on the Transition Temperature of only persist, but are strengthened, in the monolayer limit. In TiSe2, we Two- Dimensional Ferroelectrics, Shiva P. Poudel, J. Villanova, B. Miller, A. observe an orbital-selective CDW, necessarily without a kz-selectivity in Pandit, S. Barraza-Lopez, University of Arkansas, Fayetteville band hybridisation that is of key importance for the bulk instability,1 while In this presentation, I will discuss two inconsistent models for obtaining the TiTe2 is driven into a charge-ordered phase in the monolayer which is not transition temperature (Tc) of two-dimensional (2D) ferroelectrics. It will be stable in the bulk at all. In VSe2, we show how the monolayer hosts a much shown that the inconsistency arises from the choice of exchange- stronger-coupling CDW instability than the bulk, which in turn drives a correlation functional and structural constraints [1-4] by obtaining Tc for a metal-insulator transition, removing a competing instability to SnSe monolayer with PBE and vdW exchange-correlation functional, and ferromagnetism.2 Together, these studies point to the delicate balance that with increased constraints. It has been found that vdW functional gives a can be realized between competing interacting states and phases in larger Tc in comparison with PBE functional. Also, the increasing constraint monolayer transition-metal dichalcogenides. raises Tc as well. Afterward, a complete analysis of the converged unit cell This work was performed in close collaboration with M.D. Watson, A. with seven different exchange-correlation functional will be provided. Rajan, J. Feng, D. Biswas, and colleagues from the Universities of St These results represent the most comprehensive theoretical benchmarks Andrews, Oxford, Keil, Diamond, Elettra, and SOLEIL. for these intriguing 2D ferroelectric materials. 1Watson et al., Phys. Rev. Lett. 122 (2019) 076404. This work was funded by an Early Career Grant from the DOE (Grant No. 2Feng et al., Nano Lett. 18 (2018) 4493. DE-SC0016139). Calculations were performed on Cori at the National Energy Research Scientific Computing Center (NERSC), a U.S. Department 9:00am 2D+EM+MI+MN+NS+QS-TuM4 Indirect Transition and Opposite of Energy Office of Science User Facility operated under Contract No. DE- Circular Polarization of Interlayer Exciton in a MoSe2 WSe2 van der Waals AC02-05CH11231 and Arkansas High-Performance Computing Center’s Heterostructure, Hsun-Jen Chuang, A.T. Hanbicki, M.R. Rosenberger, C.S. trestles, which is funded through the multiple National Science Foundation Hellberg, S.V. Sivaram, K.M. McCreary, I.I. Mazin, B.T. Jonker, U.S. Naval grants and the Arkansas Economic Development Commission. Research Laboratory References: An emerging class of heterostructures involves monolayer semiconductors such as many of the transition metal dichalcogenides (TMDs) which can be 1. M. Mehboudi et al., Nano Lett. 16, 1704 (2016). combined to form van der Waals heterostructures (vdWHs). One unique 2. M. Mehboudi, et al., Phys. Rev. Lett. 117, 246802 (2016). new optical property of heterostructure is an interlayer exciton (ILE), a 3. S. Barraza-Lopez, et al., PRB 97, 024110 (2018). spatially indirect, electron-hole pair with the electron in one TMD layer and the hole in the other. Here, we fabricated MoSe2/WSe2 hetero-bilayer 4. R. Fei, et al., Phys. Rev. Lett. 117, 097601 (2016). encapsulated in h-BN with the alignment angle close to 60 degree between 11:00am 2D+EM+MI+MN+NS+QS-TuM10 Sign-change Pairing Symmetry MoSe2 and WSe2. Followed by the state-of-the-art preparation techniques in Single Layer FeSe/SrTiO3 Film, Huimin Zhang, West Virginia University; (Nano-squeegee) to ensure the optimal contact between the TMDs. The Z. Ge, M. Weinert, University of Wisconsin; L.L. Li, West Virginia University Strong ILE emission is observed with the emission energy around 1.35 eV at Single layer FeSe film epitaxially grown on SrTiO3(001) substrate has drawn room temperature and resolve this emission into two distinct peaks (ILE1 much interest for its novel interfacial effects, which have led to the highest and ILE2) separated by 24 meV at zero field at 5 K. Furthermore, we superconducting temperature (TC) to date amongst all Fe-based demonstrate that the two emission peaks have oppositecircular superconductors. While several paring states, such as sign-persevering s++- polarizations with up to +20% for the ILE1 and -40% for ILE2 when excited wave, sign-changing nodeless d-wave and s±-wave have been suggested, Tuesday Morning, October 22, 2019 13 8:00 AM Tuesday Morning, October 22, 2019 the pairing symmetry remains to be experimentally validated. Here we [2] L. Y. Kong et al, arXiv:1901.02293 (submitted to Nature Physics on investigate the intrinsic impurity-induced in-gap bound states and November 19, 2018) quasiparticle interference (QPI) patterns in single layer FeSe/SrTiO3 by [2] S. Y. Zhu et al, arXiv: 1904.06124 (submitted to Science on February 15, scanning tunneling microscopy/spectroscopy. We observed bound states 2019) induced by nonmagnetic impurities, which strongly suggests a sign- changing order parameter. Through detailed analysis of the phase-sensitive QPI patterns, we further confirm that the order parameter indeed changes sign within the electron pockets. This identification of a sign change pairing Thin Films Division symmetry in single layer FeSe/SrTiO3 presents a critical step towards the Room A122-123 - Session TF+EM+MI-TuM understanding of its high Tc superconductivity. Thin Films for Microelectronics, Photonics, and 11:20am 2D+EM+MI+MN+NS+QS-TuM11 High Temperature Optoelectronic Applications Superconductivity in Epitaxial Single Layer FeTe1-xSex/STO(001), Qiang Moderators: John F. Conley, Jr., Oregon State University, Halil Akyildiz, Zou, Z. Ge, C. Yan, H. Zhang, L.L. Li, West Virginia University Uludag University, Turkey Single crystal FeTe exhibits a distinct long-range bicollinear 8:00am TF+EM+MI-TuM1 Monolithic Integration of III-Vs on Si for antiferromagnetic order that can be suppressed by alloying with Se, where Electronic and Photonic Applications, P. Staudinger, S. Mauthe, N. Vico superconductivity emerges at a critical Se concentration of 0.3 with a TC of Trivino, N. Sousa, C. Convertino, Y. Baumgartner, P. Tiwari, H. Schmid, 10 K. In this work, we show that this phase transition can be further Kirsten Moselund, IBM Research Zurich, Switzerland INVITED modulated by reducing the thickness of FeTe1-xSex, downto the single For more than half a century researcher have been working on monolithic atomic layer limit. High quality single layer FeTe1-xSex films are grown on integration of III-V materials on Si in order to achieve seamless integration SrTiO3(001) substrate by molecular beam epitaxy and characterized by scanning tunneling microscopy/spectroscopy and angle-resolved of III-V with Si CMOS. Progress has been made in recent years for example photoemission spectroscopy. We find the electronic properties are strongly on nanowires [1], aspect ratio trapping (ART) [2] and other selective growth dependent on the Se content. For x < 0.1, hole-like bands cross the Fermi techniques suitable for III-V device integration. Here, I will discuss our work level and form a hole-pocket at the Γ point with no states observed around on Template-Assisted Selective Epitaxy (TASE) [3], as a novel epitaxial the M point, indicating no superconductivity. With increasing Se content, technique where III-V nanostructures are grown within an oxide template. the top of the valence bands moves away from the Fermi level, In this method we first use a combination of lithography and etching to accompanied by a decrease in effective mass at the Γ point. For x > 0.1, the define our structures in Si. These might be vertical or lateral nanowires, or hole pocket at Γ point moves below the Fermi level, and an electron-pocket more exotic shapes such as hall-bars, rings and disks. The Si features are emerges at M point where a superconducting gap opens with a TC of ~50 K. covered by an oxide, which is opened locally, and the Si is partially etched These findings and their implications for the emergence and stabilization of exposing a Si nucleation seed within a hollow oxide cavity (template). The superconductivity in Fe-based superconductors at reduced dimensions will template is subsequently filled by metal-organic chemical vapor deposition be presented at the meeting. (MOCVD) grown III-V material. The geometries of the III-V features are lithographically defined by the shape of the hollow template and to a large 11:40am 2D+EM+MI+MN+NS+QS-TuM12 The Observation of Majorana extent independent of growth conditions. Zero Mode and Conductance Plateau in an Iron-based Superconductor, Hong-Jun Gao, Institute of Physics, Chinese Academy of Sciences, China The versatility of this technique will be shown through several INVITED experimentally demonstrated devices, such as InGaAs MOSFETs [4], heterojunction tunnel FETs [5] and monolithically integrated room Majorana zero-modes (MZMs) are spatially-localized zero-energy fractional temperature optically pumped GaAs [6] and InP microdisk lasers [7]. quasiparticles with non-Abelian braiding statistics that hold great promise for topological quantum computing. Recently, by using scanning tunneling The quality of the TASE-grown material is assessed by high-resolution microscopy/spectroscopy (STM/STS), a new breakthrough of Majorana zero scanning transmission electron microscopy (HR-STEM). Devices are free mode (MZM) was achieved in a single material platform of high-Tc iron- from propagating defects and dislocations, but stacking faults are present based superconductors, FeTe0.55Se0.45, which combined advantages of as expected for selective epitaxy. By controlling the twinning, we were simple material, high- Tc, and large ratio of Δ/EF [1]. A detail STM/STS study successful in demonstrating pure wurtzite InP micro-substrates for the first of a FeTe0.55Se0.45 single crystal, also revealed the mechanism of two distinct time. We also compare lasing performance to that of devices based on classes of vortices present in this system, which directly tied with the defect-free bonded material, which currently represents the state-of-the- presence or absence of zero-bias peak [2]. To further investigated the art in terms of photonic integration. MZM, it is still needed to find a “smoking-gun” type of evidence for the This work received funding from H2020 ERC project PLASMIC (Grant No. existence of MZM, and a quantized conductance plateau is widely believed 678567), SiLAS (Grant No. 735008) and the SNF (Project 200021_156746). to be one of them. Here we report an observation of the Majorana 1. B. Mayer et al., Nano Lett., vol. 16, no. 1, pp. 152–156, 2016. conductance plateau in vortices on the iron superconductor FeTe0.55Se0.45 surface by using STM/STS [3]. We found that both extrinsic instrumental 2. Z. Wang et al., Nat. Photonics, vol. 9, pp. 837–842, 2015. convoluted broadening and intrinsic quasiparticle poisoning can reduce the 3. H. Schmid et al. Appl. Phys. Lett. 2015, 106 (23), 233101. conductance plateau value. When extrinsic instrumental broadening is 4. L. Czornomaz et al., Symp. VLSI Tech., 2015, pp. T172–T173, 2015. removed by deconvolution, the plateau is found to nearly reach a 2e2/h quantized value. The direct observation of a conductance plateau on a 5. Cutaia, D. et al., Symp. VLSI Tech., pp. 403-407, (2016). single zero-mode in a vortex strongly supports the existence and protection 6. S. Wirths et al., ACS Nano 12 (3), pp. 2169, 2018. of MZMs in this iron-based superconductor, which can serve as a single- 7. S. Mauthe et al., submitted to IEEE J. Sel. Top. Quantum Electron. (2019). material platform for Majorana braiding at relatively high temperature. 8. M. Sousa et al. , 2018 IEEE Nano, DOI: 10.1109/NANO.2018.8626223 * In collaboration with, D.F. Wang1,2, L.Y. Kong1,2, P. Fan1,2, H. Chen1, S.Y. Zhu1,2, W.Y. Liu1,2, L. Cao1,2, Y.J. Sun1,2, S.X. Du1,2,3, J. Schneeloch4, R.D. 9. P. Staudinger et al., Nano Letters, vol. 18 (12), 7856, 2018. 4 4 5 1,2,3 Zhong , G.D. Gu , Liang Fu , Hong Ding . 8:40am TF+EM+MI-TuM3 A Scheme for Better Future Technology by 1 Institute of Physics & University of Chinese Academy of Sciences, CAS, developing AlGaN based Highly Responsive Photosensing Devices, Neha Beijing 100190 Aggarwal, S. Krishna, L. Goswami, G. Gupta, CSIR-National Physical 2 CAS Center for Excellence in Topological Quantum Computation, UCAS, Laboratory, India Beijing 100190 All species on Earth are affected by UV radiation, from environment-to- humans, industrial-to-residential, defense-to-technology; a number of 3 Collaborative Innovation Center of Quantum Matter, Beijing 100190 current & futuristic applications of detecting UV radiation exist. For 4 Brookhaven National Laboratory, Upton, New York 11973, USA fabricating UV photodetectors (PDs), III-Nitrides are promising candidates 5 Dept. of Physics, Massachusetts Institute of Technology, Cambridge, due to their superior material properties such as wide-direct bandgap, high Massachusetts 02139, USA thermal conductivity, good radiation hardness, etc. Also, III-nitrides are intrinsically blind to the visible region of EM spectrum; thus, do not require References: expensive optical filters unlike existing Si-based UV PDs. Among nitrides, [1] D. F. Wang et al, Science.362, 333 (2008). AlGaN based heterostructures have gained huge interest in optoelectronic

Tuesday Morning, October 22, 2019 14 8:00 AM Tuesday Morning, October 22, 2019 applications due to their ability to tune the bandgap by modulating Al different from physical deposition techniques. Furthermore, we explored concentration which allows them to select the cut-off wavelength CSD of c-axis in-plane BaxSr1-xTiO3, which is difficult to achieve by physical depending upon the application. Further, to facilitate the integration of methods and offers unique insight into the EO behavior of this highly AlGaN based devices with existing Si technology, Si substrates were utilized tunable dielectric. X-ray diffraction and scanning transmission electron for growing AlGaN heterostructures. However, large lattice mismatch microscopy confirmed epitaxial, distorted tetragonal structures with a between AlGaN & Si may restrict the growth of defect-free AlGaN, thus a range of structural defects, and electrical and electro-optical nucleation layer is needed to avoid cracking due to tensile strain. measurements showed diminished ferroelectricity and EO response Incorporation of AlN as interlayer reforms the tensile stress in AlGaN layer compared to MBE-grown thin films or bulk BTO. ALD-grown films exhibited directly grown on Si into compressive stress which yields the desired crack- optical hysteresis with coercivity of ~10 kV/cm, an effective linear EO free epitaxial structure. In this work, extensive efforts are employed to coefficient of 26 pm/V for 40 nm films, and leakage currents caused by grow AlN on Si (111) substrate via PAMBE & successfully accomplished best oxygen vacancies. CSD-grown films did not show evidence of ferroelectric quality AlN with lowest HRXRD FWHM of 15 arcmin having screw hysteresis but maintained EO response with a coefficient of 25 pm/V and dislocation density of 8.5×108 cm−2. Then, we have performed hetero- had very low leakage current. Past reports of chemical vapor deposited epitaxial growth of AlxGa1−xN on AlN buffered Si (111) for x in 0.30-0.45 films yielded an EO coefficient of 7 pm/V. These results provide further range & discusses the compositional fluctuations associated with changes understanding into the relationship between film structure and linear EO in buffer growth parameters. As the buffer growth conditions changes, Al behavior. composition varies from 0.30-0.45 & FWHM is reduced from 55.6 to 36.4 arcmin. To realize a highly responsive UV PD, uniformly oriented AlGaN 9:40am TF+EM+MI-TuM6 Nonlinear Optical Properties of TiO2-based ALD nano-islands are grown aimed to efficiently absorb photons due to Thin Films, Theodosia Gougousi, R. Kuis, I. Basaldua, P. Burkins, J.A. Kropp, increased surface-to-volume ratio. On this, we also implemented A.M. Johnson, University of Maryland, Baltimore County interdigitated (ID) electrode configuration to collect higher photo- Nonlinear materials in thin film form are highly desirable for the generated charge carriers. The fabricated AlGaN UV PDs having cut-off development of ultrafast all-optical system on-a-chip platforms, optical wavelength of 284 nm yielded a significant enhancement in responsivity frequency converters and optical limiting applications. Conventional from 36.4 to 140.5 A/W at 2 V bias upon changing electrodes from non-ID nonlinear optical (NLO) materials are usually cut from bulk crystals or are to ID. However, the developed UV detection device exhibit high response liquids that are not suitable for integration with the contemporary towards UV with responsivity value of 182 mA/W under 2.5 V bias which is semiconductor industry process flow. The third order nonlinear response of better than the commercially available UV detectors. Conclusively, the ALD TiO2-based films is investigated using thermally managed Z-scan highly responsive AlGaN UV-PD on Si displays potential application in the technique. Some of the as-deposited films exhibit very high nonlinear development of advanced optoelectronic devices. response which is orders of magnitude higher than conventional nonlinear optical materials such as silica fibers and CS2. Thermal treatment of the 9:00am TF+EM+MI-TuM4 Correlating the Optical Property Evolution in films at 450°C for 3 hours in an oxygen rich atmosphere affects the films’ the Au-Ni Binary Thin Films: From Metastable Solid Solution to Phase optical properties and results in the loss of the high nonlinear optical Separated Alloy, Robyn Collette, Y. Wu, P.D. Rack, University of Tennessee response. TiO2 films deposited by Physical Vapor Deposition (PVD) from a Knoxville 99.9% TiO2 target at room temperature are used as control samples and Surface plasmon resonances can be sustained by metallic nanostructures their nonlinear optical response is found below the detection limit of the Z- and have been explored for potential optoelectronic device applications. scan setup. This extraordinary nonlinear optical behavior of the TiO2 ALD Metallic alloys provide a pathway to tune the plasmonic response of a films is linked to the presence of a very small at. % of TiN bonding in the material. Additionally, alloying may allow for multifunctional materials to film. We will present detailed characterization of these films by x-ray be realized. For example, Au-Ni alloys may combine the magnetic photoelectron spectroscopy, x-ray diffraction and UV-Vis absorption. The properties of ferromagnetic Ni with the plasmonic properties of Au. high level of control of the nonlinear index of refraction, n2, using the However, limited studies have been conducted on Au-Ni alloys for use in deposition process coupled with the ability of ALD to coat nonplanar plasmonic devices. Since the behavior of the alloys depends on the geometries with atomic level precision and the fact that these processes structure, it is first critical to understand the relationship between the are CMOS compatible have the potential to provide a breakthrough in structure and the optical properties of the alloy. optical device design and applications. In this study, the optical properties of Au1-xNix alloy thin films are 11:00am TF+EM+MI-TuM10 Atomic Layer Deposition on Hexagonal Ge investigated by employing a combinatorial sputtering approach. The and SiGe Nanowires for Surface Passivation, Willem-Jan Berghuis, dielectric function is measured using spectroscopic ellipsometry and is Department of Applied Physics, Eindhoven University of Technology, correlated to the composition (energy dispersive x-ray spectroscopy), and Postbus 513, 5600 MB Eindhoven, The Netherlands; W.M.M. Kessels, phases present (x-ray diffraction). As-deposited alloys form a metastable Eindhoven University of Technology, The Netherlands, Netherlands; J.E.M. solid solution, however, annealed alloys exhibited phase separation into Haverkort, E.P.A.M. Bakkers, A. Dijkstra, E.M.T. Fadaly, M.A. Verheijen, Au-rich and Ni-rich phases due to the large miscibility gap in the Au-Ni Eindhoven University of Technology, The Netherlands material system. The optical properties are then rationalized by modeling Semiconductor nanowires (NWs) are nanoscale rods with a typical length of the dielectric function of the solid solution alloys with a Drude-Critical Point a few microns. They are made of materials such as Ge, Si, InP, GaAs. Due to analytical model. Lastly, the efficacy of the model is demonstrated which their high aspect ratio, nanowires have a very high surface-to-volume-ratio, shows that the dielectric function of the phase separated alloys may be which leads to a large influence of the surface on their electronic and approximated using a composition-weighted average of two solid solution optical properties. Surface states facilitate recombination of electron-hole dielectric functions. pairs, which reduces the photovoltaic conversion efficiency of NW solar

9:20am TF+EM+MI-TuM5 Integration of Electro-optically Active BaTiO3 cells [1] or which decreases the output of NW based LEDs or lasers. The and BaxSr1-xTiO3 with Buffered Si (001) by Chemical Methods, John G. surface can also induce space charge regions in the nanowires, which Ekerdt, B.I. Edmondson, E. Lin, University of Texas at Austin; S. Kwon, greatly affects their conductivity and which can be critical in for example University of Texas at Dallas; A.A. Demkov, University of Texas at Austin; sensing applications [2]. To reach the desired performance of nanowires in M.J. Kim, University of Texas at Dallas their applications, it is important to control the surface effects.

Recent investigations into thin film BaTiO3 (BTO) show it is a promising Atomic layer deposition (ALD) is a deposition technique that allows for candidate for on-chip photonic devices due to its large linear electro-optic preparation of ultrathin films with sub-nanometer thickness control and (EO) coefficient (r > 100-1000 pm/V) relative to more conventional with an excellent conformality on high aspect ratio structures such as photonic materials such as LiNbO3 (~30 pm/V) or strained Si (~2 pm/V). nanowire arrays. For these reasons ALD is a suitable technique to cover However, such high coefficients are achieved only by costly and inherently nanowires with thin films to control the surface properties. un-scalable physical vapor deposition techniques. In recent studies, we Recently, nanowires have enabled the growth of Ge and SiGe in the have investigated chemical routes to the integration of electro-optically hexagonal diamond crystal phase [3]. In contrast to the cubic crystal phase active BTO thin films with Si, which offer faster and more scalable methods of these materials, the hexagonal crystal phase leads to a direct bandgap. of deposition. Specifically, atomic layer deposition (ALD) of 40 nm BTO The latter makes this material an interesting candidate to realize solid-state films and chemical solution deposition (CSD) of 85 nm BTO films on SrTiO3 lasers that are compatible with the current silicon-based electronics. One (STO) templates on Si (001) prepared by molecular beam epitaxy (MBE) of the important steps to accomplish this is to reduce the surface yield epitaxial BTO films with microstructure and defect nature markedly recombination losses; i.e. to passivate the surface.

Tuesday Morning, October 22, 2019 15 8:00 AM Tuesday Morning, October 22, 2019

The aim of this work is to explore the surface passivation of these symmetric (Fig. 1). The greater reduction in J at large negative ℰ, ƒasym hexagonal Ge and SiGe nanowires. We do so by covering the nanowires reversal, and reduced J-ℰ slope for the 25/2/75 and 75/2/25 devices with ultrathin films of Al2O3 prepared by thermal and plasma-assisted ALD suggest that FNT is suppressed more for emission from the smaller ΦM (PE-ALD). Secondly, we cover the wires with a stack of POx/Al2O3. The latter electrode (Al) than for TiN. FNT suppression appears greatest for the is a relatively new passivation scheme that has proven very successful for 75/2/25 device in which Ni is closest to the Al, pointing to an increase in the surface passivation of InP nanowires [4] and Si wafers [5]. The change effective barrier height, likely due to negative charge in the Al2O3. in photoluminescence (PL) of the nanowires as a function of the ALD films Capacitance (C) vs. ℰ sweeps (Fig. 2) reveal a positive voltage shift in Cmin for has been studied to assess the surface passivation and the influence of all Ni devices, consistent with negative charge. various pre- and post-treatments. Conformal coating of hexagonal Ge The asymmetry reversal demonstrates the possibility of precision defect nanowires has been realized and we have observed an improvement of the engineering of MIM tunnel devices using ALD. An in-depth discussion of J-ℰ photoluminescence for NWs covered with PE-ALD Al2O3 and POx/Al2O3. and C-ℰ, temperature-IV, frequency-CV, other impurities, and annealing will be presented. 11:20am TF+EM+MI-TuM11 Oxidation Studies of Silicon Germanium 1. Alimardani et al., APL 102 143501 (2013). (SiGe) using In-Situ Steam Generated (ISSG) and Plasma Enhanced Atomic 2. Alimardani et al., JAP 116, 024508 (2014). Layer Deposited (PEALD) Oxides, Yi Song, S. Siddiqui, C. Durfee, A. Pana, J. 3. Alimardani and Conley, Jr., APL 105, 082902 (2014). Li, M. Belyansky, S. Naczas, E.P. Stuckert, L. Jiang, J. Demarest, V. Basker, D. Guo, H. Bu, IBM Research Division, Albany, NY 12:00pm TF+EM+MI-TuM13 Improvement in the Electrical Characteristics SiGe is a versatile material for the semiconductor industry for sub-7 nm of a-ZTO based TFTs via Microwave Assisted Annealing of Channel Layer, node technology development; it can be used as a high mobility channel Sunil Uprety, M.P. Khanal, H. Lee, S. Sarwar, Auburn University; A. material in FinFET, and as multiple sacrificial layers to form channel regions Subramanian, Stony Brook University; E. Hassani, T.S. Oh, X. Zhang, Auburn in gate all around (GAA) nanosheet device architecture. Understanding University; C.Y. Nam, Brookhaven National Laboratory; M. Park, Auburn SiGe film oxidation is important for matching oxidation rates between SiGe University layers with different Ge% in nanosheet applications [1]. In this paper, a In this research, we have investigated the effect of microwave-assisted study of ISSG (800 oC) and PEALD (room temperature to 300 oC) oxidation annealing of amorphous zinc tin oxide (a-ZTO) channel layers on the processes is performed on blanket Si1-xGex films ranging from x = 0.25 to electrical characteristics of the thin film transistors (TFTs). A multi-stacked 0.80. We establish the boundaries of three distinct regions of oxidation a-ZTO layer was deposited on the oxidized Si wafer using sol-gel process. behavior for the ISSG process (Region I: 0 < x < 0.5, Region II: 0.5 < x < 0.67, The precursor solution was prepared by dissolving zinc acetate dihydrate and Region III: x > 0.67). Historically, low Ge oxidation has been extensively and tin chloride dihydrate into methoxyethanol. The solution was spin studied [2-4]. Here, we show for Region I, the ISSG oxidation rate is very coated and calcined in a hot plate at 285°C. The as-calcined a-ZTO wafers small (1.7 nm of oxide growth in 5 sec). The oxidation rate rapidly increases were microwave annealed. The microwave (MW) annealing was carried on in Region II as x increases, where it reaches a maximum (13.8 nm in 5 sec) a commercial microwave oven at different power levels with the sample at the Region II/Region III boundary, then abruptly drops in Region III as x placed in a kiln which acts as a susceptor. The films remained amorphous increases due to complete sublimation of Ge (see Figure 1). The abrupt even after MW annealing, which was evidenced by X-ray diffraction. The increase in the ISSG oxidation rate between Regions I and II makes it devices were fabricated using the microwave-annealed and as-calcined difficult to match oxide thicknesses for the wide range of Ge% utilized by samples. Hall measurement is being carried out to study the concentration nanosheet device architecture. Therefore, we studied a lower temperature and mobility of charge carries. The performance of the TFTs with as- oxidation process (PEALD) which has a lower oxidation rate. We found that calcined and MW annealed channel layers were compared. Improvement PEALD oxidation rates are unchanged across the Region I/II boundary, even in the electrical characteristics of the TFTs with MW annealed films were for higher temperatures up to 300 oC as shown in Figure 2. This enables noted. It is believed that the microwave irradiation may promote the oxide thickness matching for a wide range of Ge%. These results are enhancement of the electrical characteristics of TFTs. Further research is applicable to the development of various nanotechnologies such as being pursued to elucidate the role of microwave annealing in nanosheet and high mobility channel FinFET devices. improvement of the device performance. 11:40am TF+EM+MI-TuM12 Precision Defect Engineering of Metal/Insulator/Metal (MIM) Diodes using Localized ALD Transition 1 Metal Impurities in Al2O3 Tunnel Barriers, Konner Holden , Y. Qi, J.F. Conley, Jr., Oregon State University Thin film MIM tunnel diodes are receiving increased interest for high-speed applications such as THz detection and rectenna based energy harvesting. - + Traditionally, current density vs. field (J-ℰ) asymmetry (ƒasym = J /J ) with MIM diodes has been achieved through metal work function differences (ΔΦM). Recently, nanolaminate insulator tunnel barrier MIIM diodes enabled by ALD showed improved ƒasym, non-linearity, and responsivity at low voltage by step tunneling through the wider bandgap (EG) insulator to 1 the conduction band of the narrow EG insulator. Intrinsic defects present in narrow EG insulators were later demonstrated to further improve low ℰ asymmetry via defect enhanced direct tunneling, when paired with an insulator dominated by tunneling.2,3 In this work, we investigate the impact of localized extrinsic defects by using ALD to intentionally introduce Ni at precise intervals in an Al2O3 tunnel barrier.

ALD of Al2O3 on TiN was performed at 200 °C using TMA and H2O. Five samples were prepared in which a 100 cycle Al2O3 ALD sequence was tBu2 interrupted by two cycles (c) of Ni( DAD)2 and O3 after 25, 50, 75, and every 25 c of Al2O3. As-deposited MIM devices were tested with bias applied to an Al top electrode (Fig. 1). DC J-ℰ sweeps of the 100 c device show Fowler-Nordheim tunneling (FNT) at high ℰ, with ƒasym > 1 due to ΔΦM ≈ 0.2 eV (Fig. 1). The addition of Ni cycles in all cases leads to an increase in J at low ℰ vs. the 100 c Al2O3 device, suggesting defect related conduction. At high ℰ, however, J of all Ni devices is lower than the 100 c device, suggesting suppression of FNT. The 25/2/75 and 75/2/25 (Al2O3/Ni/Al2O3) devices show ƒasym opposite of the 100 c device, while the 50/2/50 and 25/(2/25)x3 devices are roughly

1 TFD James Harper Award Finalist Tuesday Morning, October 22, 2019 16 8:00 AM Tuesday Afternoon, October 22, 2019 2D Materials (LDOS). We showed that the overlap term can enhance the LDOS leading to Room A216 - Session 2D+EM+MI+NS-TuA stronger charge confinement in certain regions. Motivated by the work of Mason et. al (2018) we have extended these studies to a closed pack Properties of 2D Materials including Electronic, Magnetic, structure with a unit cell of 3 distinct deformations. This arrangement can Mechanical, Optical, and Thermal Properties II be extended by symmetry to a lattice superstructure, thus creating a Moderator: Roland Wiesendanger, University of Hamburg, Germany periodic array of confined charge regions, i.e, quantum dots. This array can be tailored by appropriately choosing the parameters of the deformations 2:40pm 2D+EM+MI+NS-TuA2 Resolving the Structural and Electronic and their distances. The total charge distribution in these systems is similar Properties of Graphene/Ge(110), Luca Camilli, Technical University of to those observed in twisted bilayer systems, known as ‘Moire patterns’. Denmark, Denmark; M. Galbiati, Technical University of Denmark; L. We discuss optimal tuning of deformations to control the physical Persichetti, M. De Seta, Università degli Studi Roma Tre, Italy; F. Fabbri, properties of these graphene devices. Italian Institute of Technology, Italy; A. Scaparro, Università degli Studi Roma Tre, Italy; A. Notargiacomo, Centro Nazionale di Ricerca, Italy; V. 3:20pm 2D+EM+MI+NS-TuA4 Ultrafast Spin and Charge Dynamics in Miseikis, C. Coletti, Italian Institute of Technology, Italy; L. Di Gaspare, Monolayer WSe2-Graphene Heterostructure Devices, Michael Newburger, Università degli Studi Roma Tre, Italy Y.K. Luo, The Ohio State University; K.M. McCreary, U.S. Naval Research Unraveling the structural and electronic properties of the interface Laboratory; I. Martin, E. McCormick, The Ohio State University; B.T. Jonker, between graphene and conventional semiconductors is critical to enable U.S. Naval Research Laboratory; R. Kawakami, The Ohio State University novel graphene-based applications [1]. Monolayer transition metal dichalcogenides (TMDs) have attracted attention due to their long spin/valley lifetimes and ability to couple the In this framework, the graphene/Ge(110) system has since last year helicity of light to spin/valley polarization. Additionally, a strength of TMDs received unprecedented attention [2-6]. Notably, graphene can be grown lies in their ability to complement other materials, such as graphene, by via chemical vapor deposition directly on the surface of germanium, acting as a means of optical spin injection or proximity coupling. Recently, similarly to the case of graphene grown on metals [7]. From a structural multiple groups have demonstrated proximity mediated charge transfer point of view, the graphene/Ge system is very dynamic, and the Ge surface and optical spin injection in TMD/graphene heterostructures. However, the has been shown by scanning tunneling microscopy (STM) studies to spin transfer dynamics across a TMD/graphene interface remain largely undergo a number of changes (i.e., reconstructions). However, the unexplored. conclusions drawn in those studies do not always agree, probably also due to the strong dependence of the STM images on the applied voltage bias Here we utilize time-resolved Kerr rotation (TRKR) microscopy to image the that makes comparison between different images rather difficult. In Ref. spatial dependence of spin/valley dynamics in monolayer WSe2/graphene [6], for instance, the authors report three different surface reconstructions heterostructure devices. Spatial maps demonstrate long-lived spin/valley that are driven by thermal annealing, while the authors in Ref. [4] find only lifetimes on the bare WSe2 but reveal a quenching of spin-valley signal at the unreconstructed surface and a (6x2) reconstruction, which again can the WSe2/graphene interfaces. Time delay scans show these interface reversibly change to unreconstructed surface after annealing at high lifetimes to be quenched up to 3 orders of magnitude in comparison to temperature in hydrogen. bare WSe2. Furthermore, photoluminescence mapping exhibits quenching at the interfaces while photoconductivity is enhanced in these regions, In this study, we aim at resolving the rich phase diagram of the Ge surface demonstrating efficient charge transfer from WSe2 to graphene. protected by graphene. We carry out annealing of the sample at different Consequently, we attribute the ultrafast spin/valley quenching to the temperatures, and use a low-temperature STM to investigate the surface transfer of spin information by conducted charge carriers. structure with atomic precision. At each stage, images at different applied biases are collected in order to allow a more straightforward comparison of 4:20pm 2D+EM+MI+NS-TuA7 Spatially Selective Enhancement of the results. Photoluminescence in MoS by Exciton-Mediated Adsorption and Defect Moreover, we perform electron energy loss spectroscopy (EELS) and Passivation, Saujan V. Sivaram, A.T. Hanbicki, M.R. Rosenberger, G. scanning tunneling spectroscopy (STS) at temperature below 10 K to shed Jernigan, H.-J. Chuang, K.M. McCreary, B.T. Jonker, U.S. Naval Research light on the electronic properties of the graphene/Ge interface, and to get Laboratory more insights into their interaction. Monolayers of transition metal dichalcogenides (TMDs) are promising components for flexible optoelectronic devices due to their direct band gap Finally, we also show through a combination of STM and Raman and atomically thin nature. The photoluminescence (PL) from these spectroscopy that graphene can protect the germanium surface from materials is often strongly suppressed by non-radiative recombination oxidation even after continuous exposure to ambient conditions for more mediated by mid-gap defect states. Here, we demonstrate up to a 200-fold than 12 months, which is surprisingly a far more efficient protection than increase in PL intensity from monolayer MoS2 synthesized by chemical that offered by graphene on metals [8, 9]. vapor deposition (CVD) by controlled exposure to laser light in ambient. References This spatially resolved passivation treatment is air and vacuum stable. [1] J.-H. Lee et al. Science 344, 286 (2014) Regions unexposed to laser light remain dark in fluorescence despite continuous impingement of ambient gas molecules. A wavelength [2] G. Campbell et al. Physical Review Materials 2, 044004 (2018) dependent study confirms that PL brightening is concomitant with exciton [3] J. Tesch et al. Nanoscale 10, 6068 (2018) generation in the MoS2; laser light below the optical band gap fails to [4] D. Zhou et al. Journal of Physical Chemistry C 122, 21874 (2019) produce any enhancement in the PL. We highlight the photo-sensitive [5] H.W. Kim et al. Journal of Physical Chemistry Letters 9, 7059 (2018) nature of the process by successfully brightening with a low power broadband white light source (< 10 nW). We decouple changes in [6] B. Kiraly et al. Applied Physics Letters 113, 213103 (2018) absorption from defect passivation by examining the degree of circularly [7] X. Li et al. Science 324, 5932 (2009) polarized PL. This measurement, which is independent of exciton [8]F. Zhou et al. ACS Nano 7, 6939 (2013) generation, confirms that laser brightening reduces the rate of non- radiative recombination in the MoS2. A series of gas exposure studies [9] X. Zhang et al. Physical Chemistry Chemical Physics 18, 17081 (2016) demonstrate a clear correlation between PL brightening and the presence 3:00pm 2D+EM+MI+NS-TuA3 Array of Strain Induced Quantum Dots in of water. We propose that H2O molecules passivate sulfur vacancies in the Graphene, Md Tareq Mahmud, N. Sandler, Ohio University CVD-grown MoS2, but require photo-generated excitons to overcome a Local Gaussian-shaped deformations induce strain fields that are large adsorption barrier. This work represents an important step in represented by scalar and vector potentials in a continuum model understanding the passivation of CVD-synthesized TMDs and demonstrates description of electron dynamics in graphene. The ubiquitous strain the interplay between adsorption and exciton generation. changes the charge distribution in a very peculiar way, introducing a This research was performed while S.V.S and M.R.R held a National sublattice symmetry breaking, as has been reported in the literature. This Research Council fellowship and H.-J.C. held an American Society for feature can be exploited to design specific charge profiles by combining Engineering Education fellowship at NRL. several deformations. Naturally, a combination of two or more is expected to introduce interference effects that can enhance charge accumulation in specific regions. We have investigated the effects of two overlapping deformations with different separations on the local density of states

Tuesday Afternoon, October 22, 2019 17 2:20 PM Tuesday Afternoon, October 22, 2019 4:40pm 2D+EM+MI+NS-TuA8 Strained Graphene in the Quantum Hall recent APPRES measurements and conclusions concerning its magnetic Regime: Valley Splitting and Extra Conducting Channels, Daiara Faria, state are made. The calculated phonon spectra are used in investigation of Ohio University / Universidade do Estado do Rio de Janeiro; C. León, CDW transition mechanism. Crystal structure of the CDW state is Brigham Young University; L. Lima, Universidade Rural do Rio de Janeiro, determined using the evolutionary crystal structure prediction combined Brazil; A. Latgé, Universidade Federal Fluminense, Brazil; N. Sandler, Ohio with lattice dynamics. University 6:00pm 2D+EM+MI+NS-TuA12 Tunable Band Gap and Thermal The coupling between electronic and mechanical properties in 2D materials Conductivity Measurements of Monolayer MoSe2 by S Incorporation, has become an important tool to control valleytronics. Graphene Shyama Rath, V. Singh, University of Delhi, India experiments have been reported with common deformations such as membrane bending that induces strain in the samples [1]. It has also been Monolayer MoSe2 was grown on insulating SiO2/Si substrates by chemical shown that strain affects charge distributions and graphene transport vapor deposition. Scanning electron microscopy and optical contrast properties. Motivated by these responses, we have studied the effect of images were used to determine the domain size, morphology, and the folds and wrinkles in graphene. New ’edge’-like states along the graphene number of layers. The crystallinity, and thickness of the synthesized folded region, that are valley polarized, were found and explored [2]. To domains were determined by Raman spectroscopy. The band gap was take advantage of the existence of these new states, it would be desirable determined from Photoluminescence (PL) spectroscopy. The PL emission to separate their contribution from the continuum extended states that was absent for more than 4 layers, and the peak position varied from 1.48 make graphene a semimetal. eV for 4 layers to 1.55 eV in the monolayer limit. Sulphur incorporation was done to obtain MoSxSe2-x so as to obtain a further tunability of the Here we present a theoretical study of folds effects on a graphene bandgap. The band gap changes from 1.55 eV for monlayer MoSe2 to 1.64 membrane in the quantum Hall regime. We show that the addition of an eV for monolayer MoS0.32Se0.68. Further, larger area domains were achieved external magnetic field allows the isolation of the valley polarized edge in the alloy as compared to binary. The thermal conductivity of the states in energy and in real space. Local density of state calculations in the monolayer MoSe2 and MoSxSe2-x were determined from temperature- deformation region predict the valley split peaks, as observed in recent dependant Raman spectroscopy. experimental [3]. Using recursive Green’s function method, we are able to reveal new extra conducting channels due to the "new edges” at the deformation region. These extra conducting channels could be detected in transport measurements. Complex Oxides: Fundamental Properties and Applications Focus Topic A discussion is presented to bring attention on the role of the deformation parameters on the graphene quantum Hall regime and their relations with Room A220-221 - Session OX+EM+HC+MI+NS+SS+TF-TuA the magnetic lengths. With this in mind, we perform an analytic study Complex Oxides: Catalysis, Dielectric Properties and based on the continuum (Dirac) description of electrons in graphene. In this model, the deformation is considered as a perturbation to the Landau Level Memory Applications states. The results show the existence of two different regimes, Moderators: Alexander Demkov, University of Texas at Austin, Jeffry characterized by the ratio between the magnetic length and the Kelber, University of North Texas deformation width (γ = lB/b). For γ<1 the magnetic confinement allows the 2:20pm OX+EM+HC+MI+NS+SS+TF-TuA1 Novel Multiferroic and electrons to follow the strain potential profile. In this regime, the spatial Ferroelectric Ferrite Thin Films, Peter A. Dowben, C. Binek, X. Xu, separation between the polarized currents is larger. This could encourage University of Nebraska-Lincoln INVITED the design of devices where contacts can efficiently detect these polarized Ferroelectricity and ferromagnetism are foundational to numerous currents. technologies, yet the combination of ferroelectricity and ferromagnetism, [1] Y. Jiang et al., Nano Lett. 17, 2839 (2017). namely multiferroicity, may be even more desirable. Multiferroic materials [2] R. Carrillo-Bastos et al., PRB 94, 125422 (2016). are believed to be a route to voltage controlled spintronic devices. Yet very few single phase materials are known to be ferroelectric and ferromagnetic [3] S. Li, arXiv:1812.04344. at the same time, i.e. multiferroic. Even fewer materials are fewer 5:00pm 2D+EM+MI+NS-TuA9 Unraveling the Novel Quantum Phenomena materials are magneto-electric, that is to say materials with magneto- in Two-dimensional Materials using Transport and Photoemission electric coupling, i.e. voltage control of magnetization, but without Spectroscopy, Jyoti Katoch, Carnegie Mellon University INVITED separate order parameters for magnetism (or antiferromagnetism) and The extreme surface sensitivity of two-dimensional (2D) materials provides ferroelectricity. This talk will review the electronic structure of the tri-rutile an unprecedented opportunity to engineer the physical properties of these magneto-electric antiferromagnets, like Fe2TeO6, as well as rare earth materials via changes to their surroundings, including substrate, ferrites like ReFeO3 (Re = rare earth) stabilized in the hexagonal phase. adsorbates, defects, etc. In addition, 2D materials can be mechanically Both types of materials are frequently antiferromagnetic, and, in principle, assembled layer-by-layer to form vertical or lateral heterostructures, both can exhibit magneto-electric coupling. The surface termination affects making it possible to create new material properties merely by the choice the measured spin polarization of the surface and the interface with other of the constituting 2D layers and the relative twist angle between them. In materials. This will have a significant influence on the voltage control of this talk, I will discuss our recent transport [1] and photoemission [2, 3] magnetization. We have investigated the structural and electronic results that shed light on the intricate relationship between controlled properties at the surface of these more unusual multiferroic materials external perturbations, substrate, and electronic properties of 2D using angle-resolved x-ray photoemission spectroscopy (ARXPS), materials. I will show that the decoration of the 2D materials with adatoms, complemented by x-ray diffraction (XRD), x-ray photoemission electron such as sub-lattice selective atomic hydrogenation of graphene and alkali microscopy (X-PEEM), and X-ray circular dichroism. We find that the low local symmetry, especially at surfaces, will split the electronic states, via metal doping of single layer WS2 can be utilized to tailor electronic properties and induce novel quantum phenomena in 2D landscape. spin–orbit coupling. In some cases, the result is a net spin polarization at the surface, under electric field cooling. Because of the strongly [1] Katoch et. al., Physical Review Letters 121, 136801 (2018). preferential surface termination of these types of materials, the boundary [2] Katoch et. al., Nature Physics 14, 355-359 (2018). polarization is roughness insensitive, in some cases making spintronic [3] Søren Ulstrup, et. al., arXiv:1904.06681 (2019). device applications plausible. 5:40pm 2D+EM+MI+NS-TuA11 Electronic Properties and Charge Density 3:00pm OX+EM+HC+MI+NS+SS+TF-TuA3 Potential Applications and Wave Transition in Single-layer VSe2, Kien Nguyen-Cong, P. Neto, M. Challenges for Complex Oxides in Advanced Memory and Computing Batzill, I.I. Oleynik, University of South Florida Applications, Sebastian Engelmann, T. Ando, V. Narayanan, IBM T.J. Watson Research Center INVITED Single-layer VSe2 has been recently attracted attention due to experimental observations of ferromagnetism and charge density wave (CDW) transition. As the semiconductor industry continues to push for and develop higher There are controversies from both theory and experiment concerning performance computing systems, there is also a growing trend of ferromagnetism in both bulk and single layer VSe2.In addition, CDW redeveloping or optimizing fundamental computing approaches to be more transition in VSe2 is not well understood. In this work, structural, electronic, energy efficient. The development of hardware for novel AI systems is no magnetic and CDW properties of this system are investigated using first- exception. New integration schemes, novel materials, multi-component principle calculations. The calculated electronic structure is compared with materials or even nanoscale materials and the ability to integrate all of

Tuesday Afternoon, October 22, 2019 18 2:20 PM Tuesday Afternoon, October 22, 2019 these approaches together becomes the compounded challenge. species, we explored different methods to achieve the highest oxidation Deposition and etch technologies that offer differentiating solutions to state of vanadium (5+) and tungsten (6+). The thermal stability of the as- these issues therefore need to meet somewhat conflicting demands, such deposited V2O5 and WO3 are investigated by XPS and STM systematically. as low damage processing as well as high rate processing beside many We found that when V2O5 and WO3 co-exist on the a- TiO2 surface the other issues. stability of V2O5 is improved. This work provides atomic level Novel thin films, thin film laminates and alloys promising unprecedented understanding on the V2O5/WO3/TiO2 SCR catalyst and new insights into performance are very interesting candidates to enable such computing the synergistic interactions between vanadia and tungsten oxide on the a- paradigm shifts. In particular the class of complex oxides is a very TiO2 surface. interesting area of research as they offer new phenomena such as 5:40pm OX+EM+HC+MI+NS+SS+TF-TuA11 Observation of Memory Effect ferroelectricity, ferromagnetism or high temperature conductivity. While and Fractal Surface in SrRuO3 Epitaxial Thin Films, Ratnakar Palai, new phenomena are being discovered, unraveling the fundamental physics University of Puerto Rico; H. Huhtinen, University of Turku, Finland behind these properties is a critical element for an industrial exploitation of Integration of multifunctional oxide materials (ferroelectrics and these properties. multiferroics) into silicon technology is of great technological and scientific In addition, these new and complex materials are growing the need for the interests. The current interest in functional oxides is largely based on ultimate process solution: atomic layer precision processing. Atomic layer engineered epitaxial thin films because of their superior properties etching is a promising path to answer the processing demands of new compared to the bulk and polycrystalline thin films and their technological devices at the Angstrom scale. Self-limiting reactions, discrete reaction and applications in dynamic random access memories, magnetic recording, activation steps or extremely low ion energy plasmas are some of the spintronics, and sensors. Most of these applications require bottom and pathways being pursued for precise material removal control and top electrodes to exploit the electronic properties of the functional maintaining the original film performance. Depending on the nature of the materials. material, the etch response may be either too much or not enough SrRuO3 (SRO) has been found to be very useful for electrodes and junctions chemical modifications of the material. Resulting modifications of the films in microelectronic devices because of its good electrical and thermal is an important variable to consider in the readiness of material systems. In conductivities, better surface stability, and high resistance to chemical particular synergy to deposition approaches such as atomic layer corrosion, which could minimize interface electrochemical reactions, deposition has been proposed as a solution, but more work is needed. charge injection in oxide, and other detrimental processes, thus improving 4:20pm OX+EM+HC+MI+NS+SS+TF-TuA7 Epitaxial Design of Complex retention, fatigue resistance, and imprint. It also has good work function to Oxides for Catalysis and Electrocatalysis, Yingge Du, Pacific Northwest produce the required large Schottky barrier on most ferroelectric oxide National Laboratory INVITED capacitors. Predictive synthesis of highly active and cost-effective catalysts and The bulk SRO exhibits several useful properties, such as extraordinary Hall electrocatalysts for energy conversion and storage is critical for leveraging effect, strong magnetocrystalline anisotropy, itinerant ferromagnetism, intermittently available energy sources. Transition metal oxides with and spin-glass behavior. Spin-glass materials are currently frontier field of perovskite (ABO3) and perovskite-related structures (e.g., Brownmillerite research and the most complex kind of condensed state of matter and Ruddlesden-Popper) have been identified as robust catalysts with high encountered so far in solid-state physics. Despite of the enormous oxygen reduction reaction (ORR) and/or oxygen evolution reaction (OER) importance of spin-glass models in neural networks, our knowledge of the activities that rival the performance of noble metals and their compounds. underlying mechanistic processes involved is extremely limited. Although The study of perovskites as epitaxial thin films enables measurement of memory effect has been reported in bulk SRO, to our knowledge, the their intrinsic catalytic activity, deconvolved from the effects of surface behavior is not well understood and there was no such report in thin films. roughness and polycrystalline defects (e.g., grain boundaries and edges In this work, we report on the observation of memory effect and strong between facets). In addition, epitaxial growth facilitates accurate control magnetic anisotropy in extremely smooth 1–3 Å roughness epitaxial (110) over the composition, crystallographic orientation, and strain in thin films. and (010) SrRuO3 thin films. The observation of non-zero imaginary In this talk, our recent efforts in the design of epitaxial complex oxides for susceptibility and frequency dependent cusp at freezing temperatures catalysis and electrocatalysis will be highlighted. Using LaNiO3, a bi- confirms the spin-glass behavior, which agrees well with the dc functional electrocatalyst, as an example, I will show how isovalent magnetization measurement. The origin of memory effect can be substitution, alliovalent substitution, and interfacial strain can be used to attributed to the magnetic frustration and random interaction, which is tune the structural, electronic, and optical properties of the resultant films, affected by dynamics of cooling and will be discussed in details. and how these observed changes correlate with their (electro)catalytic performance. The use of complex oxide thin films as support or anti- 6:00pm OX+EM+HC+MI+NS+SS+TF-TuA12 In situ Auger Electron corrosion layers during catalytic reactions will also be discussed. Spectroscopy of Complex Oxide Thin Film Surfaces Grown by Pulsed Laser Deposition, Thomas Orvis, M. Surendran, Y. Liu, A. Cunniff, J. 5:20pm OX+EM+HC+MI+NS+SS+TF-TuA10 Vanadia/Tungsten Oxide on Ravichandran, University of Southern California Anatase TiO2(101): a Model Catalyst Study by STM and XPS, Tao Xu, J.V. Complex oxides can enhance the functionality of electronic and photonic Lauritsen, K.C. Adamsen, Aarhus University, Denmark; S. Wendt, iNANO, devices by supplementing them with interesting properties such as Aarhus University, Denmark ferroelectricity, superconductivity, and magnetoresistivity. Furthermore, Nitrogen oxides (NOX) from flue gas are in concern as major sources of air low dimensionality in these materials can result in additional useful pollution. Increasingly stricter NOX emission control policies (e.g. Euro VI) properties, inspiring the continued study of complex oxides in thin film demand innovation and better performance of NOX reduction technology. form. However, the deposition of these materials is typically governed by The Selective Catalytic Reduction (SCR) of NOX by vanadia supported on notoriously complex growth mechanisms, revealing the need for in situ anatase titania, with tungsten oxide (WO3) as promoter, has been widely probes to observe and understand their precise nature. To this end, we used for this service and attracted much research attention. However, report the in situ observation of chemical composition of complex oxide many aspects of the SCR catalysis process remain poorly understood at the thin film surfaces with Auger electron microscopy during growth by pulsed atomic level. Particularly, the synergistic effect of tungsten oxide and laser deposition. Our implementation of real-time monitoring techniques vanadia remain elusive in literature, despite intensive RAMAN and infrared for complex oxide thin films sheds an important light on the intricacies of spectroscopy studies. the relationships between processing conditions and resulting composition. In this work, we use mineral a-TiO2 single crystals exposing the (101) facets as the model surface and deposit V2O5 and WO3 in our ultrahigh vacuum chamber (UHV) chamber by e-beam evaporation in oxygen. Combining Scanning Tunneling Microscope (STM) and X-ray photon-electron Spectroscopy (XPS), we systematically investigated the morphology and oxidation state changes of the model catalyst upon heating and reactant adsorption. The STM results illustrate the distribution of V2O5 and WO3 on anatase TiO2(101) at the atomic level. It is found that both species are highly dispersed in the sub-monolayer region. For the deposition of surface oxide

Tuesday Afternoon, October 22, 2019 19 2:20 PM Wednesday Morning, October 23, 2019 2D Materials hollow-hexagons (HH) in an otherwise triangular lattice. The vast number Room A216 - Session 2D+AS+MI+NS-WeM of possible HH lattices underlies the polymorphic nature of borophene. Superlattices of HHs could be further realized when borophene phases 2D Materials Characterization by Scanning Probe periodically intermix in the form of line defects3. While scanning tunneling Microscopy and Spectroscopy microscopy (STM) of borophene with conventional metal probes has Moderator: Adina Luican-Mayer, University of Ottawa, Canada revealed key features of borophene, significant ambiguity of the exact atomic lattice structure exists due to the convolution of electronic and 8:20am 2D+AS+MI+NS-WeM2 Silicene like Domains on IrSi3 Crystallites, structural details. With CO-functionalized atomic force microscopy, we Nuri Oncel, D. Cakir, F. Fatima, D. Nicholls, University of North Dakota unambiguously resolve the HH lattice and reveal features corresponding to Recently, silicene, the graphene equivalent of silicon, has attracted a lot of B-B covalent bonds4 that are supported by numerical simulations. We attention due to its compatibility with Si-based electronics. So far, silicene further show that CO-functionalized STM is an equivalent but more has been epitaxially grown on various crystalline surfaces such as Ag(110), accessible technique for HH imaging, allowing us to assemble a growth Ag(111), Ir(111), ZrB2(0001) and Au(110) substrates. Here, we present a phase diagram of borophene involving non-rotated, 30°-rotated and new method to grow silicene via high temperature surface reconstruction randomly rotated borophene phases on Ag(111), confirming the v1/5 and of hexagonal IrSi3 nanocrystals. The h-IrSi3 nanocrystals are formed by v1/6 models as the unifying structures for all observed phases. In particular, annealing thin Ir layers on Si(111) surface. A detailed analysis of the STM a transition from rotationally commensurate to incommensurate phases is images shows the formation of silicene like domains on the surface of some observed at high growth temperatures, corroborating the chemically of the IrSi3 crystallites. We studied both morphology and electronic discrete nature of borophene. properties of these domains by using both scanning tunneling *Current affiliation of Xiaolong Liu: Kavli Postdoc Fellow, LASSP, Cornell microscopy/spectroscopy and first-principles calculation methods. University 8:40am 2D+AS+MI+NS-WeM3 Interfacial and Topological 1. A. J. Mannix, X.-F. Zhou, B. Kiraly, J. D. Wood, D. Alducin, B. D. Myers, X. Superconductivity in 2D Layers Studied by Spin-Resolved Scanning Liu, B. L. Fisher, U. Santiago, J. R. Guest, M. J. Yacaman, A. Ponce, A. R. Tunneling Spectroscopy, Roland Wiesendanger, University of Hamburg, Oganov, M. C. Hersam, N. P. Guisinger, Science 350, 1513–1516 (2015). Germany INVITED 2. B. Feng, J. Zhang, Q. Zhong, W. Li, S. Li, H. Li, P. Cheng, S. Meng, L. Chen, In this presentation, we will first focus on interfacial superconductivity in K. Wu, Nat. Chem. 8, 563–568 (2016). novel types of heterostructures. In particular, we will present a low- 3. X. Liu, Z. Zhang, L. Wang, B. I. Yakobson, and M. C. Hersam, Nat. temperature SP-STS study of ultrathin FeTe1-xSex (x = 0, 0.5) films grown Mater.17, 783–788 (2018). on prototypical Bi-based bulk topological insulators. We observe fully developed U-shaped superconducting gaps in FeTe0.5Se0.5 layers of one 4. X. Liu, L. Wang, S. Li, M. S. Rahn, B. I. Yakobson, and M. C. Hersam, Nat. unit cell (UC) thickness with a transition temperature (Tc) of ~11 K, close to Commun. 10, 1642 (2019). the one of the corresponding bulk system (Tc ~ 14.5 K) [1]. Surprisingly, we 9:40am 2D+AS+MI+NS-WeM6 Atomic Manipulation of Defects in the also find clear evidence for superconductivity up to Tc ~ 6 K for one UC Layered Semiconductor 2H-MoTe2, Sara Mueller, S. Deng, The Ohio State thick FeTe layers grown on Bi2Te3 substrates [2], in contrast to the non- University; B. St. Laurent, University of New Hampshire; Y. Wang, W. Windl, superconducting FeTe bulk compound which exhibits bicollinear The Ohio State University; S. Hollen, University of New Hampshire; J.A. antiferromagnetic (AFM) order in a wide temperature range up to 70 K. Gupta, The Ohio State University Even more surprisingly, detailed investigations of the atomic-scale spin- Here we present a charge control of native defects in the bulk transition resolved local density of states by SP-STS reveal that superconductivity in metal dichalcogenide, MoTe2 by scanning tunneling microscopy (STM). Bulk one UC layers of FeTe grown on Bi2Te3 appears to spatially coexist with bi- MoTe2 was cleaved at room temperature in ultrahigh vacuum and imaged collinear AFM order. By using 3D-vector-resolved SP-STM techniques [3] we with a cut PtIr tip at 9K. Native defects in the MoTe2 are present find an unusual reorientation of the diagonal double-stripe spin structure throughout the sample and image with complex structure. In topographic at Fe1+yTe thin film surfaces [4]. Moreover, variable-temperature SP-STM imaging, the long-range protrusion of a bright defect indicates the species studies [5] reveal an enhanced Néel temperature for AFM spin ordering of is charged and we image the defects at different depths below the surface. the ultrathin FeTe films grown on topological insulators [6]. These findings They present with an ionization feature in tunneling spectroscopic mapping open novel perspectives for theoretical studies of competing orders in Fe- which indicates that the charge state of this defect can be manipulated by based superconductors as well as for experimental investigations of exotic the band bending caused by the tip. Voltage pulses from the tip migrate phases in heterostructures of topological insulators and superconducting the subsurface defects to the surface layer. The migrated defects present layers. with the same spectroscopic signature as native surface defects. We also In a second part, we will address experimental and theoretical studies of present DFT results that we use to clarify the identification of these native monolayer topological superconductivity and chiral Majorana edge modes defects and energy barriers for migration between layers of 2H-MoTe2. in model-type 2D magnetic Fe islands on elemental superconducting Re [7]. In particular, we demonstrate that interface engineering by an atomically 11:00am 2D+AS+MI+NS-WeM10 Scanning Tunneling Microscopy and thin oxide layer is crucial for driving the studied hybrid system into a Spectroscopy of a Heterotriangulene-based 2D Polymer, Zachery topologically non-trivial state as confirmed by theoretical calculations of Enderson, H. Murali, R. Dasari, T.C. Parker, S.R. Marder, H. Li, Q. Dai, S. the topological invariant, the Chern number. Thomas, J.-L. Brédas, P.N. First, Georgia Institute of Technology This work is supported by the EU via the ERC Advanced Grant No. 786020 Covalent Organic Frameworks (COFs) and similar materials synthesized “ADMIRE”. from bottom-up procedures grant scientists a means to customize a 2D material’s final properties from its initial precursors. The [1] A. Kamlapure et al., Phys. Rev. B 95, 104509 (2017). dimethylmethylene-bridged triphenylamine (DTPA) COF is an excellent [2] S. Manna et al., Nature Commun. 8, 14074 (2017). example of the unique systems one can fabricate with these techniques1. [3] S. Meckler et al., Rev. Sci. Instrum. 80, 023708 (2009). The DTPA COF is initially synthesized on Au(111) or Ag(111) which facilitates crystalline growth through Ullman-type coupling. With an even [4] T. Hänke et al., Nature Commun. 8, 13939 (2017). number of electrons per unit cell, theory predicts a semiconducting [5] J. Warmuth et al., NPG Quantum Materials 3, 21 (2018). electronic structure for the COF. Further heating in vacuum selectively [6] U. R. Singh et al., Phys. Rev. B 97, 144513 (2018). cleaves the dimethyl groups but leaves the framework intact. This final COF resembles an ultra-flat covalent network of triangulene molecules with [7] A. Palacio-Morales, E. Mascot, S. Cocklin, H. Kim, S. Rachel, D. K. Morr, enticing proposed electronic properties, which depend on how the and R. Wiesendanger, arXiv:1809.04503 (2018). demethylated sites are terminated. In the case of hydrogen termination at 9:20am 2D+AS+MI+NS-WeM5 Geometric Imaging of Borophene these sites, calculations indicate that the “radical” COF on a metallic Polymorphs, Xiaolong Liu, Northwestern University; L. Wang, Rice substrate will be a half-metal (fully spin-polarized density of states at the University; S. Li, M. Rahn, Northwestern University; B. Yakobson, Rice fermi energy)2. Using a low-temperature scanning tunneling microscope, University; M.C. Hersam, Northwestern University the work outlined in this talk presents new information on the electronic Two-dimensional (2D) boron, known as borophene, has recently been structure of the DTPA COF in both its intact (methylated) and radical experimentally realized1,2 revealing a number of polymorphic structures. A (demethylated) forms. common characteristic of those borophene polymorphs is the presence of Wednesday Morning, October 23, 2019 20 8:00 AM Wednesday Morning, October 23, 2019 [1] Bieri, Marco, Stephan Blankenburg, Milan Kivala, Carlo A. Pignedoli, 2D-MnGaN is strained in-plane; for example, E = -1.58 eV for the no-strain Pascal Ruffieux, Klaus Müllen, and Roman Fasel. “Surface-Supported 2D case, whereas E = -1.33 eV for tensile strain (+9.1%) and E = -2.22 eV for Heterotriangulene Polymers.” Chem. Commun. 47, no. 37 (2011): 10239– compressive strain (-6.0%). On the other hand, we find an opposite 41. https://doi.org/10.1039/C1CC12490K . behavior in the local anisotropic calculation. [2] Kan, Erjun, Wei Hu, Chuanyun Xiao, Ruifeng Lu, Kaiming Deng, Jinlong Using atomic resolution STM, we have also found that significant strain Yang, and Haibin Su. “Half-Metallicity in Organic Single Porous Sheets.” variations exist within the 2D-MnGaN. As compared to an ideally periodic Journal of the American Chemical Society 134, no. 13 (April 4, 2012): 5718– hexagonal lattice, the 2D-MnGaN lattice displays local spacing variations, 21. https://doi.org/10.1021/ja210822c . and the spacing distribution is highly non-Gaussian and may instead be characterized as tri-modal with the central peak matching closely the 11:20am 2D+AS+MI+NS-WeM11 Scanning Tunneling Microscopy expected average for 2D-MnGaN of 5.52 Å, but with left and right peaks Investigations of Molecules Adsrobed on Semiconducting Graphene centered around 5.00 Å and 5.92 Å. Therefore, the Mn atoms, centered Nanoribbons, Sineth Premarathna, K.Z. Latt, S.-W. Hla, Ohio University between Ga adatoms, are under highly varying strains, ranging from tensile Unlike graphene, semiconducting graphene nanoribbons poccess a band to compressive. gap and they have the capability to electronic decouple the molecules from the supporting substrate. Here, we study the structural, electronic and By mapping the observed Mn peak energies onto theoretical energy-strain vibrational properties of individual para-sexiphenyl molecules adsorbed on curves, we can then estimate the expected lattice parameters semiconducting graphene nanoribbons. The graphene nanoribbons here corresponding to particular energies and compare with the lattice spacing are grown on the surface of Au(111) using DBBA molecules as the initial distribution. These results will be discussed as well as the additional discovery of a dependence of the spin anisotropy on the lattice strain. building blocks. Para-sexiphenyl molecules adsorb on the graphene naribbons with their long molecular axis positioning parallel to the long axis [1] Yingqiao Ma, Abhijit V. Chinchore, Arthur R. Smith, María Andrea Barral, of the graphene nanoribbons. As expected, the tunneling spectroscopy and Valeria Ferrari, Nano Letters 18, 158 (2018). data reveal the HOMO-LUMO gap of the molecule on graphene nanoribbons much closer to their gas phase values. Moreover, teh vibration spectroscopy measurements of the molecules further provide a 2D Materials strong vibration mode associate with the C=C ring stretching of the Room A226 - Session 2D+EM+MI+MN+NS+QS-WeM molecules. This work provide single molecule level information on the electronic, vibronic and structural properties of the molecules adsorbed on Novel 2D Materials vertically stacked heterostructures formed by graphene nanoribbons on Moderator: Phil King, University of St Andrews Au(111) surface. 8:00am 2D+EM+MI+MN+NS+QS-WeM1 A Safari Through Thousands of Acknowledgement: This work is supported by the DOE-BES, DE-FG02- Layered Materials Guided by Data Science Techniques, Evan Reed, G. 02ER46012 grant. Cheon, Stanford University INVITED 11:40am 2D+AS+MI+NS-WeM12 Molecular Flexure and Atom Trapping We have utilized data mining approaches to elucidate over 1000 2D with Sexiphenyl Molecules by Scanning Tunneling Microscope materials and several hundred 3D materials consisting of van der Waals Manipulation, Y. Zhang, Shaoze Wang, K.-F. Braun, S.-W. Hla, Ohio bonded 1D subcomponents, or molecular wires. We find that hundreds of University these 2D materials have the potential to exhibit observable piezoelectric Molecular flexure, and molecule-metal contact of para-sexiphenyl effects, representing a new class of piezoelectrics. A further class of layered molecules on a Ag(111) surface are investigated by using low temperature materials consists of naturally occurring vertical hetero structures, i.e. . scanning tunneling microscopy, and molecular manipulations. Atom bulk crystals that consist of stacks of chemically dissimilar van der Waals trapping with sexiphenyl molecules is realized by laterally manipulating the bonded layers like a 2-D super lattice. We further combine this data set molecules onto individual silver atoms and up to three silver atoms have with physics-based machine learning to discover the chemical composition been trapped. We also demonstrate breaking of a silver dimer into of an additional 1000 materials that are likely to exhibit layered and two- individual silver atoms by atom trapping. STM manipulation experiments dimensional phases but have yet to be synthesized. This includes two show that the molecule-metal complexes formed by the atom trapping are materials our calculations indicate can exist in distinct structures with mechanically stable. Moreover, lateral manipulation of a single seziphenyl different band gaps, expanding the short list of two-dimensional phase across a Ag(111) atomic step highlights how the molecule moves across change materials. We find our model performs five times better than step-edges; the molecule can easily conform across the step and it recovers practitioners in the field at identifying layered materials and is comparable original configuration after the manipulation. or better than professional solid-state chemists. Finally, we find that semi- supervised learning can offer benefits for materials design where labels for Acknowledgement: This woek is supported by the DOE-BES, DE-FG02- some of the materials are unknown. 02ER46012 grant. 8:40am 2D+EM+MI+MN+NS+QS-WeM3 2D Ferroelectric Semiconductor 12:00pm 2D+AS+MI+NS-WeM13 Localized Strain Effects in Spin-Polarized α-In2Se3 for Non-Volatile Memory Applications, M. Si, Peide Ye, Purdue Density of States for 2D-MnGaN – a Room Temperature Ferromagnetic University Monolayer, Y. Ma, Ohio University; K. Meng, The Ohio State University; D. α-In2Se3 is a novel two-dimensional (2D) ferroelectric semiconductor. It has Hunt, MA. Barral, V. Ferrari, CAC-CNEA, Argentina; F.Y. Yang, The Ohio a bandgap of ~1.39 eV, room temperature ferroelectricity, the ability to State University; Arthur Smith, Ohio University maintain ferroelectricity down to a few atomic layers and the feasibility for We recently demonstrated the first observation of a 2D room-temperature- large-area growth. Based on the ferroelectric and semiconducting nature of ferromagnetic monolayer of MnGaN (2D-MnGaN) using spin-polarized the material, a ferroelectric semiconductor field-effect transistor (FeS-FET) scanning tunneling microscopy and spectroscopy. The sample is grown by was proposed and experimentally demonstrated [1]. In the FeS-FET, a molecular beam epitaxy on gallium nitride substrates. We resolved ferroelectric semiconductor is employed as the channel material while the ferromagnetic domains using SP-STM, demonstrated magnetic hysteresis gate insulator is the dielectric. The two non-volatile polarization states in using small out-of-plane magnetic fields, observed magnetic rim states, and FeS-FETs exist in the ferroelectric semiconductor channel. Therefore, a high measured magnetic DOS profiles using tunneling spectroscopy which are in quality amorphous gate insulator can be used instead of the common excellent agreement with the predicted spin-polarized & spin-split DOS polycrystalline ferroelectric insulator for Fe-FETs. The fabricated FeS-FETs peaks obtained from first-principles theory. This work was published online exhibit high performance with a large memory window, a high on/off ratio in December 2017 in Nano Letters.[1] over 108, a maximum on-current of 862 μA/μm, low supply voltage with More recently, we are investigating the dependence of magnetization scaled gate insulator and the potential to exceed the existing Fe-FETs for anisotropy on in-plane lattice strain. First of all, we have observed from the non-volatile memory applications. spectroscopy measurements that the position of the spin-polarized Mn [1] M. Si, S. Gao, G. Qiu, J. Qin, Y. Duan, J. Jian, H. Wang, W. Wu, and P. D. DOS peak varies from spectrum to spectrum, ranging from -1.69 eV up to - Ye, “A Ferroelectric Semiconductor Field-Effect Transistor,”, 1.22 eV (relative to E_Fermi). In order to investigate if these variations arXiv:1812.02933. could be related to structural variations, we have also carried out theoretical calculations based on first principles for both isotropic and local anisotropic lattice strains. The isotropic strain case shows that the occupied-states Mn peak can indeed shift by many tenths of an eV if the Wednesday Morning, October 23, 2019 21 8:00 AM Wednesday Morning, October 23, 2019

9:00am 2D+EM+MI+MN+NS+QS-WeM4 Ab initio Informed Theory of Axis- NbSe2 polymorph can be grown by molecular beam epitaxy on epitaxial dependent Conduction Polarity in Goniopolar Materials, Yaxian Wang, B. graphene/SiC(0001) substrates. A (Ö13xÖ13) Star-of-David charge density He, M.Q. Arguilla, N.D. Cultrara, M.R. Scudder, J.E. Goldberger, J.P. waves is observed by in situ scanning tunnelling microscopy, which persists Heremans, W. Windl, The Ohio State University above room temperature. A gap of 0.50 eV is further observed by

NaSn2As2 has recently been synthesized and was found to be an tunnelling spectroscopy and angle resolved photoemission spectroscopy, exfoliatable van der Waals Zintl phase, opening new opportunities for indicating that this monolayer 1T phase of NbSe2 is also a Mott insulator, electronic design on the few-atom-thick scale. Although the band structure similar to that of bulk 1T TaS2. Our findings indicate that the presence of may suggest a range of metal to semi-metal, it shows strong anisotropy epitaxial constraints can generate structural configurations that are especially in its “polarity”, characterized by its dominant carrier type, which prohibited in fully-bonded TMD crystals. These findings and their strongly affects its electronic and thermal properties. We used DFT implication on the collective electronic states of single layer 1T-NbSe2 will calculations to investigate bandstructure and Fermi surface. In addition, we be discussed at the meeting. employed BoltzTraP code to calculate the transport behavior in in/cross- 11:00am 2D+EM+MI+MN+NS+QS-WeM10 Magnetic Interfaces of MnSe2 plane directions, predicting strongly anisotropic carrier transport and Monolayer, Tomas Rojas, S. Ulloa, Ohio University directionally dependent polarity –“goniopolarity” – in this layered material. It is confirmed by experimental thermopower measurements. We show Until recently, 2D magnetism was thought to occur together with defects from simulations on a model band structure the Fermi surface geometry or doping on different substrates. This situation changed drastically, as origin in a single-band toy model, and we utilize the bandwidth concept intrinsic Cr-based ferromagnetic monolayer materials were discovered, from a tight-binding model to give an insight of real space orbital namely CrI3 and Cr2Ge2Te6. A different material, MnSe2, was predicted as contributions and nature of the bonding states in this layered crystal. Based stable ferromagnetic monolayer by first-principles calculations, and it has on that, additional candidate materials for goniopolarity can be proposed, been successfully grown on several substrates. In this study, the authors and the design space for goniopolar materials in general will be defined. confirm the intrinsic ferromagnetism of the monolayer, while for thicker samples they report an interface of the MnSe2 monolayer with bulk α- 9:20am 2D+EM+MI+MN+NS+QS-WeM5 In-Plane Mechanical Properties MnSe(111). This phase of the material is non-magnetic, and yet the and Strain Engineering of 2D Hybrid Organic-Inorganic Perovskites, Qing observed magnetic moments are of up to twice the value of those in the Tu, I. Spanopoulos, S. Hao, C. Wolverton, M. Kanatzidis, G. Shekhawat, V. monolayer alone. In this work, we present a detailed analysis of the Dravid, Northwestern University interactions at this interface between the two phases, using the Heyd- Two-dimensional (2D) hybrid organic-inorganic perovskites (HOIPs) are new Scuseria-Ernzerhof hybrid functional. We have studied the effects on the members of the 2D materials family with wide tunability, highly dynamic electronic and magnetic structure of both phases of the material, and the structural features and excellent physical properties. Mechanical strain is dependence on the sample thickness. We study the role that strain plays at inevitable in 2D-HOIP-based applications due to materials processing, the interface, and how it affects the magnetic moments of the structure. thermal expansion and substrate deformation. Understanding the Supported by NSF-DMR 1508325, and Ohio Supercomputer Center . mechanical properties and strain engineering of such functional materials are both fundamentally and practically important to achieve high 11:40am 2D+EM+MI+MN+NS+QS-WeM12 Rotationally Controlled van der performance and mechanically stable (flexible) devices. Here the in-plane Waals Heterostructures of 2D Materials, Emanuel Tutuc, K. Kim, G.W. mechanical properties and the impact of in-plane uniaxial tensile strain on Burg, H.C.P. Movva, The University of Texas at Austin INVITED the electronic properties of 2D lead iodide perovskites with a general Heterostructures of atomic layers such as graphene, hexagonal boron- formula (CH3(CH2)3NH3)2(CH3-NH3)n-1PbnI3n+1 were reported for the first nitride, and transition metal dichalcogenides (TMDs) can serve as testbed time. The in-plane Young’s modulus and breaking strength of ultrathin 2D for novel quantum phenomena in two-dimensions, and potential device HOIP flakes were measured by AFM-based nanoindentation of suspended applications. A key ingredient that can add a new dimension to the atomic 2D HOIP membranes.[1] The in-plane Young’s moduli of 2D HOIPs are layer heterostructures palette is the rotational control, and alignment of smaller than that of conventional covalently bonded 2D materials like different two-dimensional (2D) layers. We review here an experimental 4- graphene and MoS2 due to the much more deformable [PbI6] octahedra technique that enables rotationally controlled heterostructures with structure. Both the Young’s modulus and breaking strength first decrease accurate alignment of the individual layer crystal axes [1]. We illustrate the and then plateau as the thickness of 2D HOIP flake increases from applicability of this technique to the rotationally aligned double layers of monolayer to 4 layers, which is attributed to interlayer slippage during graphene [2], or TMDs [3] separated by a tunnel barrier which display deformation. Ultrathin 2D HOIPs exhibit outstanding breaking resonant, energy- and momentum-conserving tunneling in vertical strength/Young’s Modulus ratio compared to many other widely used transport, consistent with theoretical expectations. When two 2D layers engineering materials and polymeric flexible substrates, which renders are overlaid with a relative twist, the resulting heterostructure shows a them suitable for application into flexible electronic devices. Furthermore, new type of periodicity associated with the moiré superlattice, which are the uniaxial tensile strain was found to increase the band gap of 2D only beginning to be systematically investigated as platform for strongly HOIPs.[2] Such strain effect on the band gap of 2D HOIPs is fully reversible correlated electron physics. We discuss the electron transport in tunable and depends on the structural unit of the materials. For2D HOIP with n = 5, moiré patterns realized in twisted bilayer [4], and double bilayer graphene the strain response of the band gap can be as high as 13.3 meV/%. First- heterostructures. principles simulations show that the strain response of the band gap arises Work done in collaboration with S. K. Banerjee, L. F, Register, B. J. LeRoy, A. 4- from the rotation of the inorganic [PbI6] octahedra and the consequential H. MacDonald, T. Taniguchi, and K. Watanabe. Pb-I bond stretching and increase of Pb-I-Pb angle. The observed band gap– [1] K. Kim et al., Nano Lett. 16, 1989 (2016); strain relationship can be harnessed to map the local mechanical strain in 2D HOIP-based devices and allow 2D HOIPs for sensing applications. [2] G. W. Burg et al., Nano Lett. 17, 3919 (2017); G. W. Burg et al., Phys. Rev. Lett. 120, 177702 (2018). References [3] K. Kim et al., Nano Lett. 18, 5967 (2018). [1]. Tu Q, Spanopoulos I, Yasaei P, Stoumpos CC, Kanatzidis MG, Shekhawat GS, et al. Stretching and Breaking of Ultrathin 2D Hybrid Organic–Inorganic [4] K. Kim et al., Proc. Natl. Acad. Sci. USA 114, 3364 (2017). Perovskites. ACS Nano. 2018;12(10):10347-54. [2]. Tu Q, Spanopoulos I, Hao S, Wolverton C, Kanatzidis MG, Shekhawat GS, et al. Probing Strain-Induced Band Gap Modulation in 2D Hybrid Organic–Inorganic Perovskites. ACS Energy Letters. 2019;4(3):796-802. 9:40am 2D+EM+MI+MN+NS+QS-WeM6 Collective Electronic States of Epitaxial Monolayer 1T-NbSe2, Zhuozhi Ge, University of Wisconsin; H. Zhang, L. Liu, C. Yan, West Virginia University; M. Weinert, University of Wisconsin; L.L. Li, West Virginia University At the single layer limit, transition metal dichalcogenides (TMDs) can adopt two different structural variants depending on the anionic environment around the metal ions: the anions are arranged in trigonal prismatic fashion in the 1H polymorph, whereas in 1T the arrangement is octahedral. While bulk 1T NbSe2 doesn’t exist in nature, here we show that single layer 1T Wednesday Morning, October 23, 2019 22 8:00 AM Wednesday Morning, October 23, 2019 Electronic Materials and Photonics Division 8:40am EM+2D+AS+MI+MN+NS+TF-WeM3 Characterization of SiGe/Si Room A214 - Session EM+2D+AS+MI+MN+NS+TF-WeM Multilayer FIN Structures using X-Ray Diffraction Reciprocal Space Maps, Roopa Gowda, M. Korde, SUNY Polytechnic Institute; M. Wormington, Nanostructures and Nanocharacterization of Electronic and Jordan Valley Semiconductors Inc.; A.C. Diebold, V. Mukundan, SUNY Photonic Devices Polytechnic Institute Moderators: Sang M. Han, University of New Mexico, Jason Kawasaki, Nanowire and Nanosheet FET’s are potential replacements for FinFET’s, University of Wisconsin - Madison mainly beyond sub-10nm CMOS technology nodes, as gate-all-around (GAA) FET device architecture provides improved electrostatics in higher on 8:00am EM+2D+AS+MI+MN+NS+TF-WeM1 Photonic Thermal Conduction current (I on) and better subthreshold swing. As GAA is one of the best in Semiconductor Nanowires, E.J. Tervo, M.E. Gustafson, Z.M. Zhang, B.A. promising device for logic applications for future technology nodes, there is Cola, Michael A. Filler, Georgia Institute of Technology an increased need of characterization technique for such multilayer Si1- We present a practical material system—chains of infrared plasmonic xGex/ Si complex structures. We studied Si1-xGex/Si/Si1-xGex/Si/Si1- resonators situated along the length of semiconductor nanowires—where xGex/Simultilayer FIN structures using X-Ray Diffraction Reciprocal Space near-field electromagnetic coupling between neighboring resonators Maps (RSM). RSM is one of the most popular technique to study epitaxial enables photonic thermal transport comparable to the electronic and thin-films nanostructures due to straightforward analysis of the data. We phononic contributions. We model the thermal conductivity of Si and InAs found RSM simulations showing sensitivity of nanosheet fin structures nanowires as a function of nanowire diameter, resonator length, aspect dimensions such as pitch-walk (PW), Nanosheet thickness (NST), ratio, and separation distance by combining discrete dipolar approximation composition and shape. RSM’s provide better means to interpret more calculations, to determine the relevant dispersion relations, with thermal complex diffraction measurements than real space constructions. RSMs of kinetic theory. We show that photonic thermal conductivities exceeding 1 Si1-xGex/Si multilayer structure has been simulated using Bruker JV-RADS W m-1 K-1 are possible for 10 nm diameter Si and InAs nanowires containing v6.5.50/HRXRD software. 1D line profiles extracted from RSMs was also repeated resonators at 500 K, more than an order of magnitude higher used for the analysis of nanostructures dimensions. We obtained than existing materials systems and on par with that possible with phonons multilayer structure dimensions from the published information. We and electrons. These results highlight the potential for photons in properly studied the influence of nanostructure parameters PW, NST, Composition engineered solids to carry significant quantities of heat and suggest new and shape on RSMs. Imperfect periodic structures impact the intensity ways to dynamic control thermal conductivity. modulation of the grating rods (GRs). We observed that satellite peaks intensity reduces and harmonics peaks intensity enhances as PW increases. 8:20am EM+2D+AS+MI+MN+NS+TF-WeM2 Electric Field-Induced Defect Rate of intensity change in higher order peaks is much faster than the Migration and Dielectric Breakdown in ZnO Nanowires, Hantian Gao, M. lower harmonic peaks. We observed that the spacing between adjacent Haseman, Department of Physics, The Ohio State University; H. von interference fringes in RSMs is related to the thickness of the layers. The Wenckstern, M. Grundmann, Universität Leipzig, Felix-Bloch-Institut für period of fringes is inversely proportional to the thickness of the layer, Festkörperphysik; L.J. Brillson, The Ohio State University hence total FIN height can be determined. 1D line profiles along Qz shows Nanowires of the II-VI compound semiconductor ZnO have generated decreased angular width and increase in intensity of the layer peak and considerable interest for next generation opto- and microelectronics . interference fringes as NST increases. Symmetric 004 longitudinal RSMs Central to nanowire electronics is understanding and controlling native and their line profiles clearly show layer peak shift from substrate peak as 1 point defects, which can move and lead to dielectric breakdown under composition increases due to increase of SiGe lattice spacing along the applied electric fields. We used nanoscale lateral and depth-resolved growth direction. Cross-shaped GR pattern in RSMs is observed which is cathodoluminescence spectroscopy (DRCLS) with hyperspectral imaging due to trapezoidal surface grating caused by SWA. Line profiles indicate (HSI) in a scanning electron microscope (SEM) to observe defect migration that fin shapes influence the modulation of the GRs as a function of Qx. We and redistribution directly under applied electric fields and after dielectric demonstrate the characterization of complex Si1-xGex/ Si multilayers using breakdown. HSI maps represent lateral intensity distributions of specific RSMs and their line profiles which are relevant for lateral nanowire and features acquired pixel by pixel across SEM-scanned areas and normalized nanosheet FETs. Above findings from RSM simulations clearly indicate the to near band edge (NBE) emissions. A pulsed layer deposited (PLD) ZnO influence of variations in structural dimensions. microwire (3 μm diameter) exhibited homogeneous distributions of common luminescence features at 2.0 eV (VZn cluster) and 2.35 eV (CuZn) as 9:00am EM+2D+AS+MI+MN+NS+TF-WeM4 Nanoscale Depth and well as 2.7 and 2.9 eV (VZn) peaks near the wire surface. With increasing Lithiation Dependence of V2O5 Band Structure by Cathodoluminescence electrical bias up to 3x105 V/cm between two Pt contacts, these defects Spectroscopy, Mitchell Walker, N. Pronin, The Ohio State University; A. systematically redistribute, even at room temperature, moving toward and Jarry, J. Ballard, G.W. Rubloff, University of Maryland, College Park; L.J. under one of the contacts, draining the “bulk” nanowire, especially its Brillson, The Ohio State University near-surface region. Since ionized VZn-related and CuZn antisite defects are Vanadium pentoxide (V2O5) has attracted considerable interest for its acceptors, their removal reduces the compensation of electron density in potential use as a cathode for solid state lithium ion batteries. While the typically n-type ZnO and thus its resistivity. researchers have studied the V2O5 lithiation charge/discharge cycle for over Besides HSI lateral maps, DRCLS vs. incident beam energy yields depth two decades, we are only now able to measure directly its electronic band profiles radially of defects at specific locations along the nanowire. These structure from the surface to the thin film bulk and its changes with Li exhibit high near-surface and wire core densities that biasing reduces. intercalation on a near-nanometer scale. We used depth-resolved Current voltage measurements with increasing field gradients show a cathodoluminescence spectroscopy (DRCLS) to monitor the changes in gradual resistivity decrease until an abrupt dielectric breakdown of the electronic structure from the free surface to the thin film bulk several microwire at 300 kV/cm (150 V/5 μm). The acceptor removal between the hundred nm below. DRCLS measures optical transitions at 1.8-2, 3.1-3.2, contacts and their accumulation under one of the contacts can both 3.6-3.7, 4.0-4.1, and 4.6-4.7 eV between multiple conduction bands to the contribute to this breakdown due to the decrease in resistivity and higher pristine (α) V2O5 valence band maximum in excellent agreement with V3dt2g current conduction between the contacts and possible defect-assisted conduction band densities of states (DOS) predicted by density functional 1 tunneling2 across the increased defect density under the contact, theory (DFT). Triplet conduction band states at 1.8, 1.9, and 2 eV respectively. These electric field-induced defect movements may be of correspond to predicted V 3dxy–Oc 2px/2py hybridized states resulting from more general significance in understanding dielectric breakdown strong deviations of the unit cell VO6 octahedra from cubic coordination mechanism not only in ZnO nanostructures but also bulk semiconductors in correspond to optical absorption edges along the 3 crystallographic axes. general. With excitation depth increasing from < 10 to 125 nm calibrated by Monte Carlo simulations, the relative amplitudes and energies of these states HG, MH, and LJB gratefully acknowledge support from AFOSR Grant No. change, signifying gradual changes in octahedral distortion. The band FA9550-18-1-0066 (A. Sayir). HVW and MG acknowledge Deutsche structure changes significantly with Li intercalation into LixV2O5 for x = 0, 1, Forschungsgemeinschaft (Gr 1011/26- 1). and 2. Lithiation gradually removes the hybridized band and introduces a 1. G. M. Foster, et al., Appl. Phys. Lett. 111, 101604 (2017). 2.4-2.7 eV V3d t2g band extending 50 nm (x=1) or 25 nm (x=2) into the 2. J.W.Cox, et al., Nano Lett, 18, 6974 (2018). surface. Higher (4.0 and 4.4 eV) features possibly related to a secondary phase dominate the spectra deep inside all V2O5 films near the battery electrode. Delithiation reintroduces the 1.8-2 eV split-off band although significantly narrowed by octahedral distortions. Overall, DRCLS shows that

Wednesday Morning, October 23, 2019 23 8:00 AM Wednesday Morning, October 23, 2019 the lithiation cycle alters the V2O5 band structure on a scale of 10-100’s of controllable doping. Investigations of surface doping for one to few layer nm with lithiation. The direct measure of V2O5’s electronic band structure WS2 were performed using mechanically exfoliated WS2 on a SiO2/Si as a function of lithiation level provided by DRCLS can help guide future substrate that was then exposed to tris(4-bromophenyl)ammoniumyl battery engineering work as more efficient lithium ion batteries are hexachloroantimonate, a p-dopant molecule. PEEM was performed before developed. In particular, these unique electrode measurements may reveal and after p-dopant exposure. After doping, we find that the contrast of the in what ways lithiation changes V•2O5 irreversibly, as well as reveal surface WS2 physical features change and valence band edge shifts about methods to extend solid state battery life. MW and LJB acknowledge 0.8 eV away from the Fermi energy, consistent with p-doping. We will support from NSF grant DMR-18-00130. AJ and GR acknowledge discuss the effects of molecular doping in terms of homogeneity and Nanostructures for Electrical Energy Storage (NEES), a Department of surface features across multiple WS2 flakes. Lastly, we will discuss Energy Office of Science Frontier Research Center. commissioning of a new PEEM instrument installed at NIST in 2019, using results of graphene to demonstrate imaging capability and energy 1. V. Eyert and K.-H. Höck, “Electronic structure of V2O5: Role of octahedral deformation,” Phys. Rev. B 57, 12727 (1998). resolution of this instrument. 11:00am EM+2D+AS+MI+MN+NS+TF-WeM10 Hot Electron Emission from 11:40am EM+2D+AS+MI+MN+NS+TF-WeM12 Comparison of Features for Waveguide Integrated Graphene, Ragib Ahsan, F.R. Rezaeifar, H.U. Chae, Au and Ir Adsorbed on the Ge (110) Surface, Shirley Chiang, University of R. Kapadia, University of Southern California California, Davis; R.K. Xie, H.Z. Xing, Donghua University, China; T.S. From free electron laser sources to electronic structure measurements, Rahman, University of Central Florida; C.Y. Fong, University of California, electron emission devices play an important role in a wide range of areas. Davis Photoemission is one of the basic processes exploited in modern electron Two ad-atoms of Au and Ir adsorbed, respectively, on the Ge(110) surface emission devices. However, higher-order processes like multiphoton are studied by a first-principles algorithm based on density functional absorption or optical field induced emission are necessary for efficient theory. The surface is modeled by a slab consisting of 108 Ge atoms with a photoemission from high workfunction metallic emitters. Our work 10 Å vacuum region. Hydrogen atoms are used to saturate the dangling demonstrates a graphene emitter integrated on a waveguide that can orbitals at the other side of the vacuum region. Two cases of Au adsorption evanescently couple with the photons delivered from a CW laser (405 nm) and one case of Ir are reported. The case of Ir has a large binding energy and registers photoemission at a peak power that is orders of magnitude because of its small atomic size compared with the Ge atom, and the lower than previously published results based on multiphoton and optical partially filled d-states. The total energy for each case is given, as are the field induced emission processes. Coupling FDTD analysis of the waveguide energies for removing one ad-atom at a time and also both ad-atoms. The to a rigorous quantum mechanical study of the scattering mechanisms and binding energy of each case is obtained by simply taking the energy the tunneling processes in graphene, we have been able to model the difference between these configurations; this method is more realistic emission current from the graphene emitter with good agreement to the because the experimental data measured by LEEM and STM indicate that experimental data. Our investigation reveals that the photoexcited the collective motions of the ad-atoms do not allow the surface to relax to electrons can go through three mutually competitive processes: (i) its equilibrium state.[1] For a large separation in the case of two Au atoms, electron-electron scattering (ii) electron-phonon scattering and (iii) directly there is a smaller binding energy than for one ad-atom. This can relate to emission into the vacuum. Absorption of a photon causes a reduction in the fact that the collective motions seen experimentally do not happen at a the tunnel barrier seen by the electron and the emission rate increases full monolayer coverage of ad-atoms.[1] Additional comparisons will be exponentially. Integration of graphene to the waveguide enables made to an atomic model for Ir/Ge(111) from STM measurements.[2] evanescent coupling between electrons and the photons causing almost [1] B. H. Stenger et al., Ultramicroscopy, 183, 72 (2017). 100% absorption of the photons. Our integrated photonics approach [2] M. van Zijll et al., Surf. Sci. 666, 90, (2017). demonstrates an emission efficiency that is three orders of magnitude greater than free space excitation. These results suggest that integrating Support from NSF DMR-1710748 (SC, CYF); NSF DMR-1710306 (TSR); photonic elements with low dimensional materials such as 2D materials, National Natural Science Foundation of China Grants 61376102, 11174048 nanoparticles, quantum dots, etc. can provide a new domain of efficient and computational support from Shanghai Supercomputer Center (RKX, electron emission devices and integrated photonics. HZX). 11:20am EM+2D+AS+MI+MN+NS+TF-WeM11 Imaging Candidate 12:00pm EM+2D+AS+MI+MN+NS+TF-WeM13 Reference Materials for Nanoelectronic Materials with Photoemission Electron Microscopy Localization Microscopy, C.R. Copeland, R.G. Dixson, L.C.C. Elliott, B.R. Ilic, (PEEM), Sujitra Pookpanratana, S.W. Robey, National Institute of National Institute for Science and Technology (NIST); D. Kozak, K.-T. Liao, Standards and Technology (NIST); T. Ohta, Sandia National Laboratories FDA, National Institute for Science and Technology (NIST); J.A. Liddle, NIST Center for Nanoscale Science and Technology; A.C. Madison, National The drive to produce smaller and lower power electronic components for Institute for Science and Technology (NIST); J.-H. Myung, FDA; A. Pintar, computing is pushing the semiconductor industry to consider novel Samuel Stavis, National Institute for Science and Technology (NIST) nanoscale device structures, not based solely on crystalline silicon. Continued innovation and progress towards novel nanoelectronic materials As the diffraction limit fades away into the history of optical microscopy, and devices in turn requires metrologies sensitive to electronic properties new challenges are emerging in super-resolution measurements of diverse at these length scales. Tip-based imaging techniques provide electronic systems ranging from catalysts to therapeutics. In particular, due to contrast with sub-nanometer resolution, however it is a local, scanning- common limitations of reference materials and microscope calibrations, based technique. Photoemission (or photoelectron spectroscopy) is the many localization measurements are precise but not accurate. This can dominant technique to provide detailed electronic band structure result in gross overconfidence in measurement results with statistical information- level energies, dispersion, polarization dependence, etc. – but uncertainties that are apparently impressive but potentially meaningless, typically requires materials with millimeter, or larger, length scales. due to the unknown presence of systematic errors that are orders of Photoemission electron microscopy (PEEM) can be employed to allow magnitude larger. To solve this fundamental problem in measurement access to this vital information, providing full-field imaging capabilities science, we are optimizing and applying nanofabrication processes to sensitive to a variety of electronic contrast mechanisms at 10’s of develop reference materials for localization microscopy, and nanometers length scales. Here, we will present our results on imaging the demonstrating their use in quantitative methods of microscope calibration. impact of molecular dopants on multilayer tungsten disulfide (WS2) Our program consists of two complementary approaches. In the first, employing the PEEM at the Center for Integrated Nanotechnologies within involving applied metrology, we are developing reference materials such as Sandia National Laboratories. We will also discuss the commissioning of a aperture arrays that can serve as standalone artifacts for widespread recently installed PEEM to perform complementary measurements at NIST- deployment. This approach will require the application of critical- Gaithersburg. dimension metrology to establish the traceability of master artifacts, and Technological commercialization of transition metal dichalcogenides their use to calibrate a super-resolution microscope for high-throughput (TMDs) in nanoelectronics devices requires control of their electronic characterization of economical batches of reference materials. In the properties, such as charge carrier type and density, for specific device second approach, involving fundamental research, we are demonstrating functionality. Conventional techniques for doping are problematic for the application of reference materials and calibration methods in our own atomically thin 2D materials. The sensitivity of mono- to few-layer (TMDs) experimental measurements. Most interestingly, achieving vertical to their local environment and interfaces can be employed via surface integration of our two approaches and the unique capabilities that result, doping of molecules on TMDs to provide a promising route toward we are building reference materials into measurement devices for in situ calibration of localization measurements for nanoparticle characterization. Wednesday Morning, October 23, 2019 24 8:00 AM Wednesday Morning, October 23, 2019

. principles calculations to reveal the response of the (LuFeO3)m:(LuFe2O4)n superlattice. Each of the unique iron centers has excitations at slightly different energies, so by analyzing features in the dichroic rotation - which Magnetic Interfaces and Nanostructures Division are proportional to net magnetization - and the character of the optical Room A210 - Session MI+2D-WeM hysteresis loops at these energies, we reveal the magnetic field - temperature (H - T) behavior and how spin in the LuFe2O4 layer is the most Emerging Multifunctional Magnetic Materials I and significant contributor to the overall magnetic response. We also find that Magnetocaloric Materials trends in the coercive field can be interpreted in terms of how the Moderator: Greg Szulczewski, University of Alabama exchange strength depends upon the Fe site. The techniques developed here open the door to the microscopic analysis of materials with multiple 8:00am MI+2D-WeM1 Spin-dependent Electron Reflection at Materials metal centers and strong charge, spin, orbital, and lattice entanglement. with Strong Spin-orbit Interaction, Markus Donath, C. Angrick, A. Reimann, C. Datzer, A. Blob, Muenster University, Germany; J. Braun, LMU 9:20am MI+2D-WeM5 Hidden Local Spin-polarized Electronic States München,, Germany; H. Ebert, LMU München, Germany investigated by Spin- and Angle-resolved Photoelectron Spectroscopy, Taichi Okuda, Hiroshima University, Japan INVITED The reflection of electrons at surfaces becomes spin dependent due to exchange interaction in the case of ferromagnets or due to spin-orbit Spin-polarized electronic states caused by spin-orbit interaction (SOI) have interaction in the case of heavy elements. It can be used for spin- been attracted much attention recently because of the potential polarization analysis, e.g., in angle-resolved photoelectron spectroscopy in application for next-generation spintronic devices. In order to realize a single-channel mode or in multi-channel-mode detectors by using the spintronic devices for various applications, it is necessary to search various scattering target as a spin-polarizing mirror. In addition, the understanding kinds of new materials and systems possessing spin-polarized states. of the spin-dependent scattering properties provides information about Although it was believed that the breaking of structural inversion symmetry the surface barrier. We present a combined experimental and theoretical is necessary to emerge the spin-polarized electronic states by SOI, the study of the spin-dependent electron reflection at surfaces with strong possibility of spin-polarized states by the inversion symmetry breaking at spin-orbit interaction. We performed spin-dependent very-low-energy the local structure of crystals has been suggested recently[1]. Since the spin-polarization of the local structure of the other side of the crystal is electron diffraction (VLEED) experiments on Au(111), Bi2Se3, and W(110) over a wide range of energies and angles of incidence. We derived maps for opposite to maintain the zero net spin-polarization of materials, it is the reflectivity, the Sherman function, and the figure of merit and compare difficult to observe the local spin-polarization by macroscopic them with ab-initio calculations. In addition, we discuss possible working measurement and the spin-polarized states are, so to speak, hidden states. points for the use as scattering targets in spin-polarization analyzers. Spin- and angle-resolved photoelectron spectroscopy(spin-ARPES) is one of the most powerful tools to investigate the spin-polarized electronic states 8:20am MI+2D-WeM2 Competitive and Cooperative Electronic States in caused by SOI since it can measure directly the k-dependent spin- Ba(Fe1-xTx)2As2, Q. Zou, M. Fu, Z. Wu, L. Li, A.-P. Li, D.S. Parker, A. Safat, polarization of electrons in the crystal (= spin-resolved band structure). Zheng Gai, Oak Ridge National Laboratory Recent realization of high-efficiency, high-resolution and three-dimensional The electronic structure inhomogeneity in Ni, Co and Ni doped BaFe2As2 vector analysis in spin-ARPES measurement and the characteristic of the 122 single crystals are compared using scanning tunneling moderate proving depth of photoemission process enabled to investigate microscopy/spectroscopy (STM/S) at atomic level within the pure such hidden spin-polarized states. In this talk, some examples of the superconducting (SC) dome, coexisting of SC and antiferromagnetic (AFM) observation of the hidden spin-polarized states of layered materials (MoS2, phase, and non-SC phase regions. K-means clustering statistic method is PtSe2, and LaOBiSe2, etc.)[2-4] will be presented. The finding of new utilized to categorize the various nanometer-size inhomogeneous materials possessing hidden spin-polarized states largely expands the electronic states described here as ‘in-gap’, ‘L-shape’ and ‘S-shape’ states variety of spin-polarized materials and will contribute to the future immersed into the SC matrix for Ni-and Co-doped 122, and L-shape and S- application for the spintronic devices. shape states into metallic matrix for Cr-doped 122. Although the relative [1] X. Zhang, Q. Liu, J.-W. Luo, A. J. Freeman, and A. Zunger, Nat. Phys. 10, percentages of in-gap, L-shape and S-shape states various in three samples, 387 (2014). the total volume fraction of the three electronic states is quite similar, coincident with the electron (Ni0.04 and Co0.08) and hole (Cr0.04) numbers [2] R. Suzuki, M. Sakano, Y. J. Zhang, R. Akashi, D. Morikawa, A. Harasawa, doped into the 122 compound. By combining the volume fractions of the K. Yaji, K. Kuroda, K. Miyamoto, T. Okuda, K. Ishizaka, R. Arita, and Y. Iwasa, three states, local density of the states (LDOS), field dependent behavior Nat. Nanotechnol. 9, 611 (2014). and global properties in these three sets of samples, the in-gap state in SC [3] W. Yao, E. Wang, H. Huang, K. Deng, M. Yan, K. Zhang, T. Okuda, L. Li, Y. crystals is confirmed as magnetic impurity state from Co or Ni dopants, the Wang, H. Gao, C. Liu, W. Duan, and S. Zhou, Nat. Commun. 8, 14216 (2017). L-shape state is identified as the spin density wave (SDW) which competes [4] S.-L. Wu, K. Sumida, K. Miyamoto, K. Taguchi, T. Yoshikawa, A. Kimura, with the SC phase, and the S-shape state is found to be another form of Y. Ueda, M. Arita, M. Nagao, S. Watauchi, I. Tanaka, and T. Okuda, Nat. magnetic order which constructively cooperates with the SC phase rather Commun. 8, 1919 (2017). than competing with it. The comparison of the vortex structures indicates that those inhomogeneous electronic states serve as pinning centers for 11:00am MI+2D-WeM10 Compositional Tuning of Magnetic Exchange stabilizing the hexagonal vortex lattice. Interactions and Interpretation of the Pressure Dependence of the Magnetic Curie Temperature in High Entropy Alloys., Michael Mchenry, 8:40am MI+2D-WeM3 Microscopic Origin of High Temperature Carnegie Mellon University INVITED Magnetism in Multiferroic Superlattices (LuFeO3)m/(LuFe2O4)1, Janice Magnetocaloric effect (MCE) materials are of interest in a more efficient Musfeldt, S. Fan, K.A. Smith, University of Tennessee Knoxville; H. Das, A.F. technology than conventional gas compression refrigeration.MCE cooling is Rebola, Cornell University; B.S. Holinsworth, University of Tennessee environmentally friendly since ozone depleting refrigerants are not used. Knoxville; J.A. Mundy, University of California at Berkeley; C. Brooks, M. Critical rare earths metals (REs) and compounds have large MCE response Holtz, Cornell University; R. Ramesh, University of California at Berkeley; and working temperatures near room temperature. However, their D.A. Muller, D.G. Schlom, C.J. Fennie, Cornell University; S.A. McGill, scarcity, high price and corrosion limit their use. Recently, transition metal National High Magnetic Field Laboratory INVITED based high entropy alloys (HEAs) are studied for MCE applications due to Multiferroics are fascinating materials in which ferroelectric and magnetic convenient tunability of Curie temperatures,use of inexpensive orders coexist and spatial inversion and time-reversal symmetries are components and tuning of the breadth of the magnetic phase simultaneously broken. Outstanding challenges that currently prevent transformation by distributing pair-wise magnetic exchange interations on widespread application in memory and logic devices as well as a single fcc crystalline lattice. I will present our understanding of Curie neuromorphic computing include requirements for (i) a large coupling temperature, Tc, engineering in metals with direct exchange interactions as coefficient and (ii) room temperature operation. The development of a rooted in the famous Bethe-Slater curve semi-empirically derived from homologous series of superlattices with formula (LuFeO3)m:(LuFe2O4)n considerations of the chemical bond and the constraints of the Pauli offers a path forward, although questions still exist about the microscopic exclusion principle. origin of the high-temperature magnetism and the nature of the charge ordering pattern. In order to resolve these issues and provide additional The Bethe-Slater curve predicts the dependence of the magnetic exchange insight into how external stimuli like magnetic fields can control behavior, interactions on D/d where D is the transition metal interatomic spacing and we combined optical spectroscopy, magnetic circular dichroism, and first d is the spatial extend of the magnetic d-orbitals. The Bethe-Slater Wednesday Morning, October 23, 2019 25 8:00 AM Wednesday Morning, October 23, 2019 curveguides alloy design to optimize Tc‘s through distribution of exchange measurements will be correlated with microstructural and morphological interactions in MCE HEAs. I will present results for the composition and characterization of the samples. pressure dependence of the Curie temperature along with Mossbauer References spectra, for which the average hyperfine field is proportional to an average 1 Tetsuya Ikebuchi, Takahiro Moriyama, Hayato Mizuno, Kent Oda, and pairwise exchange interaction and by inference Tc. Within this formalism, we consider J(D/d), i.e. the exchange interaction(s) as a function of D/d the Teruo Ono, Appl Phys Express 11 (7), 073003 (2018). variable for which the Bethe-Slater curve is parameterized. The P- 2 Yu-Ming Hung, Christian Hahn, Houchen Chang, Mingzhong Wu, Hendrik dependence of Tcwill be interpreted for FeCoNiMnCu 5-component HEAs Ohldag, and Andrew D. Kent, AIP Advances 7 (5), 055903 (2017). with a room temperature Tc.

11:40am MI+2D-WeM12 Epitaxy of Novel Co1.5Ti0.5FeGe Heusler Alloy Thin Films, Shambhu KC1, R. Mahat, T.J. Evans, S. Budhathoki, G.J. Mankey, A. Complex Oxides: Fundamental Properties and Applications Gupta, P. LeClair, The University of Alabama Focus Topic While the half-metallic ferromagnets are considered ideal candidates to be Room A220-221 - Session OX+EM+MI+SS-WeM used for efficient spintronics devices, a single-phase microstructure with Electronic and Magnetic Properties of Complex Oxide promising half-metallic character is recently reported in a bulk 1 Co1.5Ti0.5FeGe Heusler alloy . This alloy has Ti substitution for Co atoms in Surfaces and Interfaces the parent Co2FeTiGe alloy, where the parent alloy does not exhibit half- Moderators: Yingge Du, Pacific Northwest National Laboratory, Vincent metallic behavior2. However, the Ti substitution is useful not only to Smentkowski, GE-Research stabilize single-phase behavior but also to tune half-metallicity by the Fermi 8:00am OX+EM+MI+SS-WeM1 Charge Transfer in Lanthanum Ferrite- level shift. In this work, successful growth of epitaxial thin films of this Strontium Nickelate Superlattices, Le Wang, Z. Yang, M.E. Bowden, Pacific novel Co1.5Ti0.5FeGe alloy on a-plane sapphire and MgAl2O4(100) by using Northwest National Laboratory; J.W. Freeland, Argonne National DC magnetron sputtering will be reported. In-situ reflection high energy Laboratory; Y. Du, S.A. Chambers, Pacific Northwest National Laboratory electron diffraction shows that the films grow epitaxially with smooth Charge transfer at oxide interfaces can drive emergent phenomena that do surfaces. X-ray diffraction analysis confirms the epitaxial relation and lattice not occur in the bulk, thereby significantly enriching our fundamental parameters within a few percent of the reported bulk value. Presence of understanding of these material systems and their applications. Designing finite size Laue oscillations in the XRD pattern and 0.035˚ full width at half oxide heterostructures and seeking new and novel interfacial phenomena maximum of rocking curve obtained in case of films grown on a-plane has been an active area of research for some time. We have synthesized a sapphire describe excellent quality of the films. The presence of series of [(LaFeO3)m/(SrNiO3-d)n]z ([(LFO)m/(SNO)n]z) superlattices (SLs) (z = 7 superlattice peaks; (200) and (111), indicate a strong tendency to form the to 21) by oxide molecular beam epitaxy on (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) L21 structure. The degree of B2 ordering is estimated to be as high as 0.92 (001) substrates. In situ RHEED patterns and x-ray diffraction showing that intermixing between the atoms in the octahedral and measurements reveal a high degree of structural quality in the SLs. X-ray tetrahedral sites is limited. Atomic force microscopy shows that the films photoemission spectroscopy (XPS) shows that the Fe is Fe4+ in the grown on MgAl2O4(100) are atomically smooth with a rms roughness of 0.2 (LFO1/SNO1)21 SL. However, the Fe 2p binding energy shifts to lower values nm. Magnetic measurements of films grown at 800ºC show that the with increasing LFO layer thickness in (LFOm/SNO1)z SLs, suggesting that the saturation magnetization is in close agreement with the bulk value. Angle- volume averaged Fe valence decreases. Fe L-edge X-ray absorption dependent magnetization measurements show the symmetry of the spectroscopy (XAS) measurements corroborate the XPS results, indicating coercivity is consistent with a magnetocrystalline anisotropy. Temperature- that Fe is 4+ for the (LFO1/SNO1)21 SL and mostly 3+ for the (LFO5/SNO1)10 dependent transport measurements show metallic behavior and an SL. On the other hand, Ni L-edge XAS shows that Ni valence is Ni3+ for the ordinary magnetoresistance as high as 1.55 % is obtained at 100 K. All the (LFO1/SNO1)21 SL as is also true for insulating NdNiO3, suggesting that the Ni above results describe the feasibility of growing good quality epitaxial films layers in this SL are insulating, which is consistent with our in-plane of novel Co1.5Ti0.5FeGe alloy with the structural and magnetic properties transport measurements. However, for the (LFO5/SNO1)10 SL, the Ni valence consistent with reported bulk properties. is larger than 3+. The measured energy shifts suggest that Ni is close to 4+. 1. KC et al., Tunable Properties and Potential Half-Metallicity in (Co2- The thicker LFO layer in the (LFO5/SNO1)10 SL may result in a larger band xTix)FeGe Heusler Alloys; an Experimental and Theoretical Investigation, offset and create a potential well to trap the holes in the Ni layer, inducing submitted to Phys. Rev. Materials. the formation of Ni4+. Our ongoing studies are probing the impact of the 2. Kumar et al., First-principles Calculation and Experimental Investigations SNO layer thickness on material structure as well as the evolution of the Fe on Full-Heusler Alloy Co2FeGe, IEEE Transactions on Magnetics 45, 3997 and Ni valences in (LFO5/SNOn)z SLs. Additional planned experimental and (2009). theoretical investigations will address how charge transfer from Fe to Ni occurs at the LFO/SNO interface, and how to stabilize the unusual high 4+ 12:00pm MI+2D-WeM13 Spin Transport in NiO Measured with valence in Fe4+ and Ni4+ by means of interfacial engineering. Ferromagnetic Resonance, G.J. Mankey, T.J. Evans, S. KC, Arjun Sapkota, T. Mewes, The University of Alabama 8:20am OX+EM+MI+SS-WeM2 Self-healing Growth of LaNiO3 on Mixed- Recently, a measured spin diffusion length of approximately 22 nm was terminated (LaAlO3)0.3-(Sr2AlTaO6)0.7, Friederike Wrobel, H. Hong, S. Cook, reported for spin current transmission through polycrystalline NiO.1 The T.K. Andersen, D. Hong, C. Liu, A. Bhattacharya, D.D. Fong, Argonne diffusion length is inferred by referencing the effective Gilbert damping National Laboratory constant in NiO/Fe20Ni80 bilayers as a function of NiO and Fe20Ni80 thickness. Epitaxial LaNiO3 (LNO) thin films and superlattices are known to be We present results using a different approach to determine the spin antiferromagnetic and weakly insulating for LNO thicknesses of 2 unit cells diffusion length, using trilayers of Fe20Ni80/NiO/Pt with FMR measurements but paramagnetic and metallic for higher LNO thicknesses [1]. The quality covering the frequency range of 4 GHz to 50 GHz. The Pt serves as a spin of the single-crystal substrate surface, and in particular the chemical sink when deposited directly on Fe20Ni80 and strongly increases the composition of the surface, is known to be a key factor governing the effective damping parameter. With NiO between the Pt spin sink and the quality of the deposited thin film. For SrTiO3 (001) substrates, there are ferromagnetic Fe20Ni80, the increase in damping parameter is diminished, well-established preparation methods to ensure that the surface is TiO2- and the decay length is extracted from measurements as a function of NiO terminated and atomically smooth; the only features that appear with thickness. Our preliminary measurements show that the decay length is atomic force microscopy are the regular steps and terraces associated with smaller than 15 nm consistent with a decay length of approximately 4 nm crystal miscut. SrTiO3 is therefore often preferred as a substrate over other determined from inverse spin hall effect measurements of Y3Fe5O12/NiO/Pt materials like (LaAlO3)0.3-(Sr2AlTaO6)0.7 (LSAT), whose surface composition is structures.2 In addition, at lower FMR frequencies (4 GHz as compared to harder to control. Interestingly, for unknown reasons, the highest quality 22 GHz) multiple resonances are observed for polycrystalline NiO, LaNiO3 thin films have been grown on mixed-terminated, untreated LSAT suggesting that ferromagnetic impurities are present in the (001) substrates [2, 3]. At present, very few detailed studies have been antiferromagnet. conducted regarding the precise influence of the substrate on thin film Results for polycrystalline and epitaxial trilayers will be presented, showing growth behavior due to the need for an in-situ, atomic-scale the effect of processing conditions on the spin diffusion length. These characterization technique. Exploiting an in-situ, oxide molecular beam epitaxy (MBE) chamber at the Advanced Photon Source, we were able to monitor the deposition of thin films of LNO on LSAT (001) substrates with 1 Falicov Student Award Finalist Wednesday Morning, October 23, 2019 26 8:00 AM Wednesday Morning, October 23, 2019 different surface compositions. Both non-resonant and resonant (Sr K- oxides on semiconductors. Thinner films (a few unit cells, u.c.) are known edge) X-ray scattering measurements were conducted at several points to result in flat-band heterojunctions in which the valence (conduction) during the growth process. We observed the formation of atomically band offset is large (small). However, we have recently found that thicker smooth, high-quality LNO films regardless of the initial substrate surface films (~30 u.c.) of SrNbxTi1-xO3 (0 ≤ x ≤ 0.2) on intrinsic Si(001) result in composition, suggesting that any excess, non-stoichiometric material on completely different electronic structures. Transport data suggest sharp the initial LSAT substrate rises to the surface during deposition. With upward band bending in the Si, leading to hole gas formation at the atomic layer-by-atomic layer MBE under the right conditions, we can interface, and a large (~2 eV) built-in potential in the SNTO, along with therefore achieve self-healing growth behavior of complex oxides on top of surface depletion. We have probed these buried interfaces using hard x-ray mixed-terminated substrates. We will discuss details of the in-situ growth photoelectron spectroscopy (HAXPES). The resulting core-level spectra measurements and the methods used to determine the atomic and exhibit unusual features not seen in thinner films, and not credibly ascribed chemical structures. to secondary phases or many-body effects. In order to interpret these line 1. Frano, A., et al., Orbital Control of Noncollinear Magnetic Order in Nickel shapes, we hypothesize that they result from large built-in potentials Oxide Heterostructures. Physical Review Letters, 2013. 111(10): p. 106804. within the system. We have developed an algorithm to extract these potential profiles by fitting heterojunction spectra to linear combinations 2. Liu, C., et al., Counter-thermal flow of holes in high-mobility LaNiO3 thin of spectra from phase-pure, flat-band materials, summed over layers films. Physical Review B, 2019. 99(4): p. 041114. within the probe depth, each with a binding energy characteristic of the 3. Wrobel, F., et al., Comparative study of LaNiO3/LaAlO3 heterostructures potential at each depth. This approach leads to excellent agreement with grown by pulsed laser deposition and oxide molecular beam epitaxy. experiment and band-edge profiles completely consistent with those from Applied Physics Letters, 2017. 110(4): p. 041606. transport data. Moreover, we find that the built-in potentials extracted from HAXPES on the Si side of the interface are in quantitative agreement 8:40am OX+EM+MI+SS-WeM3 Optoelectronics with Oxides and Oxide with those resulting from solving Poisson’s equation using the SIMS profile Heterostructures, Alexander Demkov, University of Texas at Austin for in-diffused oxygen from the STO. Oxygen is a shallow donor in Si, and INVITED assuming 100% donor ionization, along with the 18O SIMS depth profile, Si photonics is a hybrid technology combining semiconductor logic with fast leads to near-perfect agreement with HAXPES. broadband optical communications and optical information technologies. With the increasing bandwidth requirement in computing and signal 11:20am OX+EM+MI+SS-WeM11 Structural and Dielectric processing, the inherent limitations in metallic interconnection are Characterization of Epitaxial Entropy-Stabilized Oxide Thin Films, George seriously threatening the future of traditional IC industry. Silicon photonics Kotsonis, J.-P. Maria, Pennsylvania State University can provide a low-cost approach to overcome the bottleneck of the high The emergence of entropy-stabilized oxides (ESOs) represents a new data rate transmission by replacing the original electronic integrated paradigm for complex oxide engineering. The large configurational entropy circuits with photonic integrated circuits. The development has proceeded of ESOs facilitates mixing of chemically dissimilar cations in significant along several avenues including mounting optical devices based on III-V proportions. ESO research continues to intensify as the oxide community semiconductors and/or LiNbO3 (LNO) on Si chips, incorporation of active works toward a thorough understanding of structure-property-synthesis optical impurities into Si, and utilization of stimulated Raman scattering in relationships. Due to inherent metastability, high energy, non-equilibrium Si. All these approaches have had limited success. Recently, another path synthesis techniques are well suited for ESO fabrication. In particular, laser to Si photonics through epitaxial integration of transition metal oxide films ablation has excelled at producing high quality epitaxial ESO thin films, was demonstrated when an effective electro-optic (Pockels) coefficient of which provide a platform for fundamental characterization. BaTiO3 ( BTO) films epitaxially grown on Si via an SrTiO3 buffer was We present the growth and characterization of Ba(Ti0.2Sn0.2Zr0.2Hf0.2Nb0.2)O3 reported to be an order of magnitude larger than that in commercially- and similar Barium-based perovskite structured ESO thin films grown by available LNO modulators. More generally, epitaxial growth of SrTiO3 on laser ablation. Crystal structure, surface morphology, and optical properties Si(001) enables monolithic integration of many functional perovskite oxides are characterized by X-ray diffraction, atomic force microscopy, and on Si, including ferroelectric BTO, ferromagnetic LaCoO3, photocatalytic ellipsometry respectively. Epitaxial thin film capacitor structures were TiO2 and CoO, and many others. fabricated to characterize the frequency, voltage, and temperature In this talk, I will focus on two materials systems integrated on Si (001) and dependence of electrical properties. well-suited for implementation in the next-generation optical technologies: By exploiting the entropy-stabilized nature of ESOs, we demonstrate the SrTiO3/LaAlO3 quantum wells and Pockels-active BTO thin film incorporation of significant amounts of aliovalent cation pairs (e.g. Sc3+Ta5+) heterostructures. Both materials systems are promising for use in a wide in hopes of producing nano-polar regions supporting a dispersive dielectric variety of optical and electro-optical devices central to integrated photonic response similar to relaxor ferroelectrics. Additionally, we explore technologies, including quantum cascade lasers, photodetectors, electro- compositional space in search of a phase boundary between a high- optic modulators and switches. The resulting devices achieve refractive symmetry ESO phase and a lower symmetry end-member. Compositions at index tuning with power consumption many orders of magnitude less than such a boundary may exhibit phase instability and enhanced dielectric previously reported. Taken together, these two approached will hopefully functionality similar to compositions at or near a morphotropic phase open the door for the development of new kinds of optical and electro- boundary. The compositional degrees of freedom available in ESO systems optical devices for use in integrated photonics technologies. provide new avenues for property tuning and studying the effects of 9:20am OX+EM+MI+SS-WeM5 Medard W. Welch Award Lecture: Defect- extreme chemical disorder on dielectric properties. Mediated Coupling of Built-in Potentials at Buried Interfaces Involving 11:40am OX+EM+MI+SS-WeM12 Oxygen Vacancy-Mediated Epitaxy: Epitaxial Complex Oxides, Scott. A Chambers1, Pacific Northwest National TiO2(111)/Al2O3(0001) and Ferromagnetic Cr2O3(0001)/TiO2(111), C. Laboratory INVITED Ladewig, F. Anwar, Jeffry Kelber, University of North Texas; S.Q.A. Shah, Semiconductor-based devices are of broad importance, not only in P.A. Dowben, University of Nebraska-Lincoln electronics, but also in energy technology. Internal electric fields dictate The formation of all-oxide heterostructures comprising multiferroic oxides the flow of charge that occurs both laterally and vertically. The associated interfaced with appropriate semiconducting substrates is a promising path potential profiles can be approximated from electronic transport data, and towards low power, voltage-switchable spintronics, including non-volatile also calculated via Poisson-Schrodinger modeling, provided the properties memory and multi-functional logic devices. At the same time, the of the constituent materials and interface structures are sufficiently well necessary scaling of film thicknesses to the nm range can induce structures understood. These approaches work well for heterostructures involving, for and properties sharply different than those of the bulk. We report here in instance, III-V semiconductors. However, when complex oxides are situ XPS, LEED, EELS and ex-situ MOKE data on the growth and properties involved, they become unreliable because of poorly understood defects of Cr2O3(0001) on TiO1.7(111) on Al2O3(0001). The data indicate that the that can be present. There is, therefore, a critical need for new methods to presence of O vacancies during film growth can mediate the further growth enable the determination of band-edge profiles in heterostructures of oxides with unusual structures and properties. These data show that (a) involving these materials. O vacancies during initial stages of film growth yield a TiO2 film of an The SrTiO3/Si(001) interface has been a prototypical system for unusual crystallographic orientation and structure; and that (b) this leads understanding the materials physics and electronic structure of crystalline to growth of an epitaxial Cr2O3 layer exhibiting magnetic ordering above the expected Néel temperature of thin film chromia - indicative of a strained chromia lattice due to epitaxial growth on a substrate with a 1 Medard W. Welch Award Winner Wednesday Morning, October 23, 2019 27 8:00 AM Wednesday Morning, October 23, 2019 lattice constant of 5.1 Å, compared to the bulk chromia lattice constant of -6 4.9 Å. Molecular beam epitaxy (MBE) of Ti at 500 K in 10 Torr O2 on Al2O3(0001) initially yields TiO1.7(111) with the structure of corundum phase Ti2O3 (a = b=5.1 Å). Further deposition and annealing in O2 results in stoichiometric TiO2(111), but with the same lattice structure and orientation as Ti2O3(111), and with a total thickness of 5 nm. This is sharply different from the generally observed growth of TiO2(001) on Al2O3(0001). MBE of ~ 1 monolayer of Cr on TiO2(111) yields hexagonally-ordered Cr2O3 and the formation of titania oxygen vacancies. MOKE measurements confirm that this chromia layer is magnetically ordered at 280 to 315 K, likely antiferromagnetically ordered, with exchange bias coupling to the TiO1.7(111) substrate. O vacancies in the TiO2(111) lattice exhibit weak ferromagnetic behavior, as is evident in the In-plane MOKE, enhancing the canting of the magnetism away from the thin film normal, which is expected for the Cr2O3(0001) alone. These data demonstrate that careful control of initial growth conditions and film stoichiometry during oxide MBE can template the subsequent growth of stoichiometric oxide heterostructures with non-bulk like structures and properties. Acknowledgement: Work at UNL was supported in part by the Semiconductor Research Corporation (SRC) as task 2760.002 and NSF through ECCS 1740136. 12:00pm OX+EM+MI+SS-WeM13 Incorporation of Ti into Epitaxial Films of Magnetite, Tiffany Kaspar, S.R. Spurgeon, D.K. Schreiber, S.D. Taylor, M.E. Bowden, S.A. Chambers, Pacific Northwest National Laboratory Magnetite, Fe3O4, exhibits metallic conductivity via electron hopping between Fe2+ and Fe3+ occupying octahedral sites in the spinel lattice. As Ti4+ is doped into the octahedral sites of magnetite (the titanomagnetite series), an equal fraction of Fe3+ is reduced to Fe2+ to maintain charge neutrality. The site occupancies of Fe2+ and Fe3+ determine the transport properties of the titanomagnetite series; the end-member ulvöspinel, 2+ 3+ Fe2TiO4, exhibits p-type semiconducting transport properties. The Fe /Fe site occupancy remains controversial, but is likely in part a function of the lattice strain induced by doping smaller Ti4+ into the lattice. Here, we have deposited titanomagnetites and ulvöspinel as well-defined epitaxial thin films on MgO, MgAl2O4, and Al2O3 substrates by oxygen-plasma-assisted molecular beam epitaxy. The incorporation of Ti into the magnetite lattice is found to depend strongly on deposition conditions and substrate orientation. We have characterized the crystalline structure, phase segregation, and surface morphology with XRD, STEM/EDS, APT, and AFM, and related these to the kinetic and thermodynamic factors determined by the deposition conditions. The Fe valence state is evaluated with in situ XPS. The impact of film structure and Fe oxidation state on the electrical transport properties of the films will be discussed.

Wednesday Morning, October 23, 2019 28 8:00 AM Wednesday Afternoon, October 23, 2019 magnetic phases in many samples under various growth conditions. This competition results in inverted hysteresis loops (common in Magnetic Interfaces and Nanostructures Division superparamagnetic nanoparticles) and negative remanent magnetization. Room A210 - Session MI+2D-WeA While transmission electron microscopy images show pristine epitaxial growth, the data supports that there are regions of different magnetic Emerging Multifunctional Magnetic Materials II order. This results in interesting magnetic measurements, that share Moderators: Valeria Lauter, Oak Ridge National Laboratory, Axel similarities with ferrimagnets with competing magnetic lattices. In this talk, Hoffmann, Technical University of Berlin the time, field and temperature dependence of these samples will be discussed to help understand this phenomenon. Sample growth and 2:20pm MI+2D-WeA1 Field and Current Control of the Electrical optimization were supported by NSF (DMR-1608656), national facility Conductivity of an Artificial Two-Dimensional Honeycomb Lattice, Deepak measurements and theory were supported by the U.S. Department of Singh, University of Missouri INVITED Energy, Office of Science, Office of Basic Energy Sciences under Award Two-dimensional magnetic nanostructured geometry, such as an artificial Number DE-SC0016176, and optical measurements by American Chemical magnetic honeycomb lattice, provides facile platform to explore many Society (PRF #56642-ND10). We acknowledge the support of the National novel properties of magnetic materials in one system. Originally envisaged Institute of Standards and Technology, U.S. Department of Commerce, in to explore the physics of effective magnetic monopoles and magnetic field- providing the neutron research facilities used in this work. induced avalanche of Dirac string, artificial magnetic honeycomb lattice has emerged as a key playground to discover new and exotic magnetic phases, 4:40pm MI+2D-WeA8 Optically Induced Magnetization through Spin such as magnetic charge ordered state and the spin solid state, in disorder States at Perovskite/Ferromagnetic Interface Revealed by Neutron free environment. We have created a new artificial permalloy honeycomb Magnetoreflectivity Studies, Bin Hu, University of Tennessee Knoxville lattice of ultra-small connected element, with a typical length of ~ 12 nm, INVITED in this pursuit. Using neutron scattering and complementary This presentation reports an optically induced magnetization at measurements on the newly created honeycomb lattice, we have perovskite/ferromagnetic interface realized at room temperature. By using investigated emergent phenomena of short-range quasi-spin ice and long neutron magnetoreflectivity measurement, it was found that a circularly range spin solid order. Additionally, two new properties of Wigner crystal polarized light of 405 nm induces a magnetization with the thickness up to type state of magnetic charges and magnetic diode-type rectification are 5 nm into the surface of perovskite (MAPbBr3) film underneath of discovered in the newly created artificial honeycomb lattice. The new ferromagnetic Co layer at room temperature. On contrast, a linearly findings create a new vista for the next generation design of spintronics polarized light does not generate any detectable magnetization within the devices in this two-dimensional frustrated geometry. Research at MU is perovskite surface in the MAPbBr3/Co sample during the neutron supported by the U.S. Department of Energy, Office of Basic Energy magnetoreflectivity measurement. This observation provides an evidence Sciences under Grant No. DE-SC0014461. to show optically induced magnetization on the perovskite surface in contact with Co surface. Furthermore, the MAPbBr3/Co interface 3:00pm MI+2D-WeA3 Emergence and Dynamics of Magnetic Order in demonstrates a magneto-capacitance phenomenon, indicating that the Metamagnetic Nanostructures, Vojtech Uhlir, CEITEC BUT, Brno University electrical polarization on perovskite surface is coupled with magnetic of Technology, Czech Republic INVITED polarization on the Co surface. On the other hand, a circularly polarized The advantage of ferromagnetic materials is the nonvolatility of the light leads to spin states in hybrid perovskites through photoexcitation. The information encoded in the internal magnetic configuration, which can be observed magnetization indicates that circularly polarized light-generated used for memory storage, logic and sensing devices. Antiferromagnets are spin states can directly interact with electric-magnetic coupling, leading to another class of magnetic materials that features nonvolatile magnetic an optically induced magnetization. ordering, yet its applications have been largely overlooked until recently [1]. In materials featuring a first-order metamagnetic phase transition 5:20pm MI+2D-WeA10 Effect of Interlayer and Underlayers on the between the antiferromagnetic (AF) and ferromagnetic (FM) states, the Microstructure and Magnetic Softness in FeGa-based Ferromagnetic nature of the phase transition can be tuned by strain, pressure, chemical Composites, Adrian Acosta, K. Fitzell, University of California, Los Angeles; doping, temperature, as well as magnetic and electric fields, potentially C. Dong, Northeastern University; M. Zurbuchen, N.X.S. Sun, J.P. Chang, offering very high recording densities and huge changes in the order University of California, Los Angeles parameters controlled with very low power. Magnetoelectric materials provide the ability to efficiently control magnetism with electric fields, which is key to circumvent the size and Moreover, metamagnetic materials are outstanding candidates for finding efficiency limitations of traditional electric dipole antennas. Strain- and exploiting new functionalities and emergent phenomena on the mesoscale [2,3]. For instance, the transition from the AF order to FM order mediated multiferroic antennas, composed of individual ferromagnetic and piezoelectric phases, have recently generated a lot of interest due to the in sub-micron-wide FeRh wires becomes greatly asymmetric when comparing the heating and cooling cycles [3,4]. This recovery of the abrupt potential to reduce the size of antennas by up to 5 orders of magnitude through the coupling of magnetization and electric polarization via strain at transition in nanostructures could lead to low-energy, efficient routes to the interface. However, this requires a low-loss magnetic material with control magnetic properties, leading to potential applications, for instance, in spintronics. strong magnetoelastic coupling at high frequencies. Galfenol (Fe81Ga19 or FeGa) is a promising candidate material due to its Furthermore, we show the dynamic response of the electronic and large magnetostriction (~275 ppm in polycrystalline bulk) and large magnetic order to ultrafast laser excitation can be followed by time- resolved photoemission electron spectroscopy [5], which unlike techniques piezomagnetic coefficient (>2 ppm/Oe) but is highly lossy at high microwave frequencies. Previously, nanoscale laminates were fabricated probing the total magnetization in the sample provides a direct comparison to the dynamic response of the structural order. via DC magnetron sputtering of FeGa with NiFe as an interlayer material resulting in a composite with a small coercive field (<20 Oe), narrow FMR [1] T. Jungwirth, X. Marti, P. Wadley, and J. Wunderlich, Nature Mater.11, linewidth (<35 Oe), and high relative permeability (>1000) [1]. In this work, 231 (2016). the enhancement in soft magnetic properties is correlated to the [2] F. Pressacco et al., Sci. Rep.6, 22383 (2016). microstructure of these composites by TEM analysis where the [3] V. Uhlíř, J. A. Arregi, and E. E. Fullerton, Nat. Commun.7, 13113 (2016). nanolayering strategy promotes the formation smaller grain sizes. Optical magnetostriction measurements displayed an enhanced magnetostriction [4] J. A. Arregi et al.,J. Phys. D: Appl. Phys.51, 105001 (2018). beyond that expected from averaging the individual FeGa and NiFe phases, [5] F. Pressacco et al., Struct. Dyn. 5, 034501 (2018). indicating an interfacial contribution present leading to increase of the overall magnetostriction. The magnetostriction sensitivity peaks at a lower 4:20pm MI+2D-WeA7 Time Dependence in La0.7Sr0.3MnO3 Thin Films with magnetic field (23 Oe for FeGa/NiFe multilayers vs 56 Oe for FeGa). To Magnetic Competition, Mikel B. Holcomb, R.B. Trappen, N.M. Mottaghi, delineate the impact of the microstructure of FeGa on the soft and S.F. Yousefi, G. Cabrera, G. Bhandari, M.S.S. Seehra, West Virginia functional magnetic properties, FeGa was sputter deposited onto several University materials (NiFe, Ta, Cu, and Al2O3) as underlayers on a Si substrate which La0.7Sr0.3MnO3 is a strongly correlated ferromagnetic system, commonly can directly influence the polycrystalline structure and enhance its soft proposed for many magnetoresistance applications. Utilizing many magnetic properties [2]. XRD and AFM are used to show the dependence of techniques (bulk magnetometry, neutron reflectometry and resonant x-ray the coercivity, FMR linewidth, and magnetostriction on the texture, magnetic scattering), we observe magnetic competition between different Wednesday Afternoon, October 23, 2019 29 2:20 PM Wednesday Afternoon, October 23, 2019 internal stress, grain size, and surface roughness of the FeGa film with the 3 N. Mottaghi, R.B. Trappen, S. Kumari, C.Y. Huang, S. Yousefi, G.B. Cabrera, different underlayer materials. M. Aziziha, A. Haertter, M.B. Johnson, M.S. Seehra, and M.B. Holcomb, J. Integration of these engineered composites into a strain-mediated Phys. Condens. Matter 30, 405804 (2018). multiferroic shear wave antenna design further demonstrates the potential 4 N. Mottaghi, M.S. Seehra, R. Trappen, S. Kumari, C.-Y. Huang, S. Yousefi, of FeGa-based laminates for use in microwave communications systems for G.B. Cabrera, A.H. Romero, and M.B. Holcomb, AIP Adv. 8, 056319 (2018). implantable medical devices. 5 M. Pękała, J. Appl. Phys. 108, 113913 (2010). References: [1] Rementer, C. R., et al. (2017). Applied Physics Letters 110(24): 242403. [2] Jung, H., et al. (2003). Journal of Applied Physics 93(10): 6462-6464. 5:40pm MI+2D-WeA11 Tunable Spin-polarized Edge Effects in Transition Metal Dichalcogenides on FM and AFM Substrates, N. Cortes, Universidad Tecnica Federico Santa Maria, Chile; Oscar Avalos-Ovando, Ohio University; L. Rosales, P. Orellana, Universidad Tecnica Federico Santa Maria, Chile; S. Ulloa, Ohio University We explore proximity-induced ferromagnetism (FM) and antiferromagnetism (AFM) on transition metal dichalcogenide (TMD), focusing on molybdenum ditelluride (MoTe2) ribbons with zigzag and/or armchair edges, deposited on either a FM or an AFM substrate, e.g. such as FM europium oxide and AFM manganese oxide. A three-orbital tight- binding model allows to model MoTe2 monolayer structures in real space, incorporating the exchange and Rashba fields induced by proximity to the substrate. For in-gap Fermi levels, electronic modes in the nanoribbon are strongly spin-polarized and localized along the edges, acting as 1D conducting channels with tunable spin-polarized currents. We also study the effect of atomic defects on the 1D conducting channels and on the spin-polarized currents, finding that even in the presence of either Te and/or Mo vacancies, the spin-polarized current is nonvanishing. Hybrid structures such as the MoTe2/FM-substrate and/or MoTe2/AFM- substrate configuration can serve as building blocks for spintronic devices and provide versatile platforms to further understand proximity effects in diverse materials systems. [1] N. Cortes et al, Phys. Rev. Lett. 122, 086401 (2019). [2] N. Cortes et al, in preparation (2019). N.C. acknowledges support from Conicyt grant 21160844, DGIIP and the hospitality of Ohio University. L.R. and P.A.O. acknowledge FONDECYT grant 1180914 and DGIIP USM internal grant. S. E. U. and O. A.-O. acknowledge support from NSF DMR-1508325. 6:00pm MI+2D-WeA12 Magnetocaloric Properties of Thin Film La0.7Sr0.3MnO3: Magnetic Field Dependence and Effects of Superparamagnetism, Navid Mottaghi1, M.S.S. Seehra, C.-Y. Huang, S. Kumari, S. Yousefi Sarraf, G. Cabrera, G. Bhandari, R.B. Trappen, M.B. Holcomb, West Virginia University La0.7Sr0.3MnO3 (LSMO) with Curie temperature TC ≈ 370 K is one of the manganites which has been of interest for applications in magnetic memory devices and spintronics.1 The magnetic properties of LSMO thin films are also known to depend on the thickness of the films.2 Recent magnetic investigations of a 7.6 nm LSMO film grown by pulsed laser deposition (PLD) showed it to have a TC ≈ 290 K with a magnetic dead layer d ≈ 1.4 nm which demonstrated behavior consistent with containing superparamagnetic (SPM) spin clusters with blocking temperature TB ≈ 240 K.3,4 Here we report magnetocaloric properties of this LSMO thin film for temperatures T ≤TC in magnetic fields H up to 4 kOe. In particular, magnetic entropy SM(T, H) is evaluated from the isothermal plots of magnetization (M) vs. H at different temperatures (Fig. 1) using the Eq. ∆SM (T,H)= ∑i [(Mi+1 (Ti+1, H) - Mi (Ti, H))/(Ti+1-Ti)] ∆H. The H-dependence of ∆SM (T,H) is analyzed n using the relation (-∆SM)=aH , where a is a constant and n =2/3 is expected 5 at T = TC. Our fit of the data to this Eq. for several T ≤ TC in Fig. 2 shows n ~ 1 for T < TC with the magnitude of n increasing for T > TC. This deviation of n from n = 2/3 is likely due to presence of SPM spin clusters in the dead layer for T < TC. The larger magnitudes of n for T > TC is due to the Curie-Weiss variation of the magnetization in this regime.5 References 1 N. Izyumskaya, Y. Alivov, and H. Morkoç, Crit. Rev. Solid State Mater. Sci. 34, 89 (2009). 2 M. Huijben, L.W. Martin, Y.-H. Chu, M.B. Holcomb, P. Yu, G. Rijnders, D.H.A. Blank, and R. Ramesh, Phys. Rev. B 78, 94413 (2008).

1 Falicov Student Award Finalist Wednesday Afternoon, October 23, 2019 30 2:20 PM Thursday Morning, October 24, 2019 2D Materials presence of d0 ferromagnetism. The magnetization is reduced and the Room A216 - Session 2D+EM+MI+NS+QS+SS-ThM coercive field is increased post Mn doping which suggests the anti- ferromagnetic alignment of Mn dopant atoms. Density Functional Theory Dopants, Defects, and Interfaces in 2D Materials calculations support the Mn anti-ferromagnetic alignment hypothesis and a Moderator: Evan Reed, Stanford University ground state with Mn in the 3+ valence. This study provides important information on the role of dopants and vacancies in dilute magnetic 8:00am 2D+EM+MI+NS+QS+SS-ThM1 Interfacial Engineering of semiconductor quantum dot materials for applications in photovoltaics and Chemically Reactive Two-Dimensional Materials, Mark Hersam, spintronics. Northwestern University INVITED Following the success of ambient-stable two-dimensional (2D) materials 9:00am 2D+EM+MI+NS+QS+SS-ThM4 Interaction of Molecular O2 with such as graphene and hexagonal boron nitride, new classes of chemically Organolead Halide Nanorods by Single-Particle Fluorescence Microscopy, reactive layered solids are being explored since their unique properties Juvinch Vicente, J. Chen, Ohio University hold promise for improved device performance [1]. For example, The photoluminescence (PL) of organolead halide perovskites (OHPs) is chemically reactive 2D semiconductors (e.g., black phosphorus (BP) and sensitive to its surface conditions, especially surface defect states, making indium selenide (InSe)) have shown enhanced field-effect mobilities under the PL of small OHP crystals an effective way to report their surface states. controlled conditions that minimize ambient degradation [2]. In addition, At the ensemble level, when averaging a lot of nanocrystals, the 2D boron (i.e., borophene) is an anisotropic metal with a diverse range of photoexcitation of OHP nanorods under inert nitrogen (N2) atmosphere theoretically predicted phenomena including confined plasmons, charge leads to PL decline, while subsequent exposure to oxygen (O2) results to density waves, and superconductivity [3], although its high chemical reversible PL recovery. At the single-particle level, individual OHP nanorods reactivity has limited experimental studies to inert ultrahigh vacuum photoblinks, whose probability is dependent on both the excitation conditions [4-7]. Therefore, to fully study and exploit the vast majority of intensity and the O2 concentration. Combining the two sets of information, 2D materials, methods for mitigating or exploiting their relatively high we are able to quantitatively evaluate the interaction between a single chemical reactivity are required [8]. In particular, covalent organic surface defect and a single O2 molecule using a kinetic model. This model functionalization of BP minimizes ambient degradation, provides charge provides fundamental insights that could help reconcile the contradicting transfer doping, and enhances field-effect mobility [9]. In contrast, views on the interactions of molecular O2 with OHP materials and help noncovalent organic functionalization of borophene leads to the design a suitable OHP interface for a variety of applications in photovoltaics spontaneous formation of electronically abrupt lateral organic-borophene and optoelectronics. heterostructures [10]. By combining organic and inorganic encapsulation 9:20am 2D+EM+MI+NS+QS+SS-ThM5 Complementary Growth of 2D strategies, even highly chemically reactive 2D materials (e.g., InSe) can be Transition Metal Dichalcogenide Semiconductors on Metal Oxide studied and utilized in ambient conditions [11]. Interfaces, T.E. Wickramasinghe, Gregory Jensen, R. Thorat, Nanoscale and [1] A. J. Mannix, et al., Nature Reviews Chemistry, 1, 0014 (2017). Quantum Phenomena Institute; S.H. Aleithan, Nanoscale and Quantum [2] D. Jariwala, et al., Nature Materials, 16, 170 (2017). Phenomena Institute, Saudi Arabia; S. Khadka, E. Stinaff, Nanoscale and [3] A. J. Mannix, et al., Nature Nanotechnology, 13, 444 (2018). Quantum Phenomena Institute A chemical vapor deposition (CVD) growth model will be presented for a [4] A. J. Mannix, et al., Science, 350, 1513 (2015). technique resulting in naturally formed 2D transition metal dichalcogenide [5] G. P. Campbell, et al., Nano Letters, 18, 2816 (2018). (TMD) based metal-oxide-semiconductor structures. The process is based [6] X. Liu, et al., Nature Materials, 17, 783 (2018). on a standard CVD reaction involving a chalcogen and transition metal oxide-based precursor. Here however, a thin metal oxide layer, formed on [7] X. Liu, et al., Nature Communications, 10, 1642 (2019). lithographically defined regions of a pure bulk transition metal, serves as [8] C. R. Ryder, et al., ACS Nano, 10, 3900 (2016). the precursor. X-ray diffraction and cross -sectional SEM studies show [9] C. R. Ryder, et al., Nature Chemistry, 8, 597 (2016). insight into the type and thickness of the metal oxide created during [10] X. Liu, et al., Science Advances, 3, e1602356 (2017). optimal growth conditions. The chalcogen reacts with the metal oxide, forming TMD material which migrates outward along the substrate, leading [11] S. A. Wells, et al., Nano Letters, 18, 7876 (2018). to lateral growth of highly-crystalline, mono-to-few layer, films. In addition 8:40am 2D+EM+MI+NS+QS+SS-ThM3 Effects of Mn Doping on the Surface to displaying strong luminescence, monolayer Raman signatures, and Electronic Band Structure and Bulk Magnetic Properties of ZnS and CdS relatively large crystal domains, the material grows deterministically and Quantum Dot Thin Films, Thilini K. Ekanayaka1, G. Gurung, University of selectively over large regions and remains connected to the bulk metallic Nebraska-Lincoln; G. Rimal, Rutgers University; S. Horoz, Siirt University, patterns, offering a scalable path for producing as-grown two-dimensional Turkey; J. Tang, T. Chien, University of Wyoming; T. Paudel, A.J. Yost, materials-based devices. University of Nebraska-Lincoln 9:40am 2D+EM+MI+NS+QS+SS-ThM6 Kagome-type Lattice Instability and Semiconducting quantum dots (QDs) are desirable for solar cells due to the Insulator-metal Transition in an Alkali-doped Mott Insulator on Si(111), ability to tune the band gap by changing the QD size without changing the Tyler Smith, H. Weitering, University of Tennessee Knoxville underlying material or synthesis technique. Doping QDs with a transition The 1/3 ML monolayer (ML) ‘alpha phase’ of Sn on Si(111) is a remarkable metal is one way of further tailoring the electronic band structure and platform for the study of strong correlations in a spin ½ triangular adatom magnetic properties of QDs in order to improve overall device lattice. In this work, we employ an adatom doping scheme by depositing performance. Understanding the mechanisms causing the change in the potassium onto the triangular Sn lattice. The K-atoms destabilize the parent electronic band structure and magnetic properties due to transition metal Mott insulating phase and produce a charge-ordered insulator, revealing a doping is important to device-by-design schemes. In this study, we rare Kagome lattice at the surface. Scanning Tunneling Microscopy and measure the effects of Mn dopants on the surface electronic band Spectroscopy reveal a phase transition from an insulating kagome lattice to structure of ZnS and CdS QDs using scanning tunneling a metallic triangular lattice at about 200 K. DFT band structure calculations microscopy/spectroscopy and photoemission spectroscopy. In both the ZnS for this kagome system [J. Ortega et al., unpublished] reveal the presence and CdS systems, a decrease in band gap upon introduction of Mn is of a flat-band just below the Fermi level, making this novel system a observed. Additionally, a rigid band shift was observed in ZnS upon Mn compelling platform for hole-doping studies of magnetic and/or doping It is argued, using X-ray photoemission spectroscopy, that the rigid superconducting instabilities. band shift is due to a hole-doping mechanism caused by the formation of Zn vacancies accompanied by a Mn3+oxidation state which leads to the 11:00am 2D+EM+MI+NS+QS+SS-ThM10 Chemical Migration and Dipole reduction in total S vacancies as compared to the undoped ZnS system. No Formation at TMD/TI Interfaces, Brenton Noesges, T. Zhu, The Ohio State band shift was observed in CdS upon Mn doping, but a strong sp-d University; D. O'Hara, University of California, Riverside; R. Kawakami, L.J. hybridization takes place which results in a significant band gap reduction. Brillson, The Ohio State University Furthermore, induced midgap states originating from the Mn dopant Proximity effects at the interface between two materials can induce appear in the surface electronic band structure of Mn: CdS. Measurements physical properties not present in either material alone. Topological of the magnetization of Mn doped and undoped ZnS and CdS confirms the insulators (TIs) such as Bi2Se3 with non-trivial surface states are sensitive to interface proximity effects where overlayers and adsorbates can act as a dopant source, chemically interact with the TI surface, or couple across the 1 National Student Award Finalist Thursday Morning, October 24, 2019 31 8:00 AM Thursday Morning, October 24, 2019 TI surface states leading to novel quantum phases. Transition metal Magnetic Interfaces and Nanostructures Division dichalcogenides (TMDs), a class of 2D van der Waals materials, are a Room A210 - Session MI+2D+AS+EM-ThM promising candidate to control this interface given the shared general hexagonal symmetry and wide range of TMD properties. However, the Novel Magnetic Materials and Device Concept for Energy interface between TMDs and Bi2Se3 can be more complex than the ideal efficient Information Processing and Storage van der Waals interface. Chemical species exchange like metal cation Moderators: Mikel B. Holcomb, West Virginia University, Markus Donath, exchange and selenium migration from substrate to growing film can Westfälische Wilhelms-Universität Münster, Germany impact the structure and properties of either layer. Self-assembly mechanisms have also been observed where complete metal monolayers 8:00am MI+2D+AS+EM-ThM1 Using Novel Magnonic Device Concepts for form inside the Bi2Se3 quintuple layer [1]. We used x-ray photoelectron Efficient Information Processing, Burkard Hillebrands, Technical University spectroscopy (XPS) connected in vacuo via UHV suitcase to a molecular Kaiserslautern, Germany INVITED beam epitaxy (MBE) system to investigate chemical interaction at the In the field of magnonics, wave-based logic devices are constructed and interface between selenide TMDs and Bi2Se3. Air-free transferring is crucial studied based on the utilization of spin waves and their quanta - magnons. to minimize contamination at the interface and prevent oxidation in the The field is developing rapidly due to its potential to implement innovative air-sensitive TMDs. We compare the effects of ultrathin pure Mn metal ways of data processing as a CMOS complementary technology. Basic overlayers and monolayer MnSex on Bi2Se3 to pristine Bi2Se3. In the case of building blocks of magnonics have already been realized. Examples are pure Mn metal on Bi2Se3, Bi core levels exhibit a 1.7 eV shift toward lower linear and nonlinear spin-wave waveguide structures, magnonic logic, as binding energies while the Mn core levels also show signs of Mn-Se well as magnonic amplifiers such as the magnon transistor and parametric bonding. These core level changes indicate that, in the absence of excess Se amplification. during growth, Mn pulls Se from the substrate leaving behind Bi2 bilayers In this talk, I will give an overview about the fundamentals and the current near the surface. Depositing a monolayer of MnSex produces very different trends in magnonics. One topic is the realization of new functionalities and results than the pure metal case. Bi2Se3 core levels measured below the devices by using novel concepts borrowed from integrated optics and monolayer MnSex film exhibit a rigid 0.8 eV chemical shift toward higher combining them with the specific advantages found in magnetic systems. binding energies indicative of surface/interface dipole formation. The Examples are directional couplers and quantum-classical analogy devices, presence of this dipole is likely due to growth of primarily α-MnSe instead such as a magnonic Stimulated Raman Adiabatic Passage (STIRAP) device. of the 1T-MnSe2 2D phase [2]. Scanning tunneling microscopy (STM) height maps and spectroscopy data provide further evidence of majority α-MnSe Another important direction is to use fundamentally new macroscopic formation. XPS core level analysis combined with controlled depositions, quantum phenomena such as a Bose-Einstein condensate (BEC) at room air-free transfers and surface analysis can provide a consistent explanation temperature as a novel approach in the field of information processing of chemical diffusion and dipole formation at a TMD/TI interface. This work technology. Very promising is the use of magnon supercurrents driven by a is supported by NSF MRSEC under award number DMR-1420451. phase gradient in the magnon BEC. I will demonstrate evidence of the formation of a magnon supercurrent along with second magnonic sound, [1] J. A. Hagmann et al., New J. Phys. 19, 085002 (2017). and its spatiotemporal behavior, which is revealed by means of time- and [2] D.J. O’Hara et al. Nano Lett., 18(5), 3125-3131 (2018). wavevector-resolved Brillouin light scattering (BLS) spectroscopy. I will conclude with an outlook. 11:20am 2D+EM+MI+NS+QS+SS-ThM11 Atomically Resolved Electronic Properties of Defects in the in-plane Anisotropic Lattice of ReS2, Adina 8:40am MI+2D+AS+EM-ThM3 Spin-Polarized Scanning Tunneling Luican-Mayer, University of Ottawa, Canada Microscopy of <10 nm Skyrmions in SrIrO3/SrRuO3 Bilayers, Joseph Among the layered transition metal dichalcogenides, the compounds that Corbett, J. Rowland, A. Ahmed, J.J. Repicky, The Ohio State University; K. exhibit in-plane anisotropy are of particular interest as they offer an Meng, The Ohio State Univesity; F.Y. Yang, M. Randeria, J.A. Gupta, The additional tuning knob for their novel properties. In this talk, we present Ohio State University experimental evidence of the lattice structure and properties of We imaged isolated <10 nm sized skyrmions in SrIrO3 on SrRuO3 by spin- semiconducting ReS2 by using scanning tunneling microscopy and polarized scanning tunneling microscopy. We fabricated bilayers of 2 unit spectroscopy (STM/STS). We demonstrate that rhenium atoms form cells of SrIrO3 atop of 10 unit cells of SrRuO3 via off-axis sputtering. This diamond-shaped clusters, organized in disjointed chains and characterize thickness combination was selected because it showed a strong topological the semiconducting electronic band gap by STS. When imaging the surface hall signal. We observed a granular morphology of SrIrO3 mounds with rare of ReS2, we encounter “bright” or “dark” regions indicating the presence of patches of exposed SrRuO3. We can distinguish SrIrO3 from SrRuO3 by charged defects that will electrostatically interact with their environment. scanning tunneling spectroscopy where, SrIrO3 grains show a gap-like By spatially mapping the local density of states around these defects, we feature, while SrRuO3 have states near the Fermi level. The height explore their origin and electrostatic nature. Experimental results are histogram of the observed granular structures is consistent with an average compared with ab-initio theory. of 2 unit cells of SrIrO3. The grains of the SrIrO3 appear to act as a nucleation for skyrmion formation. Similarly, we’ve imaged skyrmions 12:00pm 2D+EM+MI+NS+QS+SS-ThM13 Size-independent “Squeezed” under applied +/- 1 T fields demonstrating their magnetic character by Shape of Metal Clusters Embedded Beneath Layered Materials, A. Lii- observing an inversion in magnetic contrast. We found that the number of Rosales, Ames Laboratory and Iowa State University; S. Julien, K.-T. Wan, SrIrO3 unit cells did not determine skyrmion formation, but the size of the Northeastern University; Y. Han, Ames Laboratory and Iowa State skymrion was linked to the grain size, i.e. the skyrmion formed roughly the University; K.C. Lai, Iowa State University; M.C. Tringides, J.W. Evans, size of the grain. Furthermore, we’ve been able to manipulate the Patricia A. Thiel, Ames Laboratory and Iowa State University skyrmions by utilizing the influence of the tip. On-going investigations into We have developed a continuum elasticity model for metals embedded the mechanism of the magnetic manipulation of the skyrmion are beneath the surfaces of layered materials. The model predicts that the underway, as well theoretical modeling of the isolated skyrmion to equilibrated cluster shape is invariant with size, manifest both by constant ascertain the local Dzyaloshinskii-Moriya interaction constant. side slope and by constant aspect ratio (width:height ratio). This prediction is rationalized by dimensional analysis of the relevant energetic 9:00am MI+2D+AS+EM-ThM4 Relieving YIG from its Substrate Constraints contributions. The model is consistent with experimental data for Cu and - YIG Resonators on Various Crystalline Substrate Materials, Georg Fe clusters embedded in graphite, especially in the limit of large clusters. Schmidt, Martin-Luther-Universität Halle-Wittenberg, Germany INVITED For comparison, we have performed a Winterbottom analysis of the We have recently demonstrated the fabrication of free-standing 3D yttrium equilibrium shape of an uncovered Cu cluster supported on top of graphite. iron garnet (YIG) magnon nano-resonators with very low damping [1]. At The aspect ratio of the embedded cluster is about an order of magnitude first the resonators were fabricated on gallium gadolinium garnet (GGG) higher than that of the supported cluster. Analysis of key energetics substrates which are most suitable for epitaxial deposition of YIG. The indicates that this is due to the strain energy (resistance to deformation) of process involves room temperature deposition and subsequent annealing. the top graphene membrane, which effectively squeezes the metal cluster Transmission electron microscopy investigation of the bridge-like and forces it to adopt a relatively low, flattened shape. These insights may structures shows that the span of the bridge is almost monocrystalline be useful for developing components such as metallic heat sinks or while some defects nucleate at the transitions from the span to the posts electrodes in electronic devices that use two-dimensional or layered of the bridge which are epitaxially bound to the substrate. This suggests materials. that the quality of the span may only indirectly depend on the quality of the feet, the latter being largely determined by the lattice matching of the

Thursday Morning, October 24, 2019 32 8:00 AM Thursday Morning, October 24, 2019 substrate material to the YIG. Being able to grow YIG structures on potentially support anti-skyrmions. We prepared a Pt/Fe(110) sample and substrate materials other than GGG would not only be interesting because found that the DMI is anisotropic with the strongest DMI along the [001] of availability and price but also because the high frequency properties of direction, which coincides with the magnetic easy axis. GGG are less than ideal while other materials like MgO or Sapphire would Finally, we studied the impact of He+ ion irradiation on DMI for the be preferred for high frequency applications. We have fabricated YIG Ta/CoFeB/Pt system. We found that the DMI increases with the dose bridges on various substrate materials including yttrium aluminium garnet before it drops for the highest does. This is in contrast to the perpendicular (YAG), MgO, and sapphire. In most cases we achieve high crystalline quality anisotropy, which continuously decreases with ion-irradiation. of the span even for non-matching substrates. For some of the materials time resolved magneto optical Kerr microscopy even reveals magnon 11:40am MI+2D+AS+EM-ThM12 Transport in Goniopolar and (pxn) resonances with reasonable linewidth. Metals, Joseph Heremans, B. He, L. Zheng, Y. Wang, M.Q. Arguilla, N.D. [1] F. Heyroth et al. cond-mat.1802.03176 Cultrara, M.R. Scudder, J.E. Goldberger, W. Windl, The Ohio State University INVITED 9:40am MI+2D+AS+EM-ThM6 Magnetic Textures in Chiral Magnet MnGe semiconductors that have p-type conduction along some crystallographic Observed with SP-STM, Jacob Repicky, J.P. Corbett, T. Liu, R. Bennett, A. directions and n-type conduction along others due to a particular topology Ahmed, The Ohio State University; J. Guerrero-Sanchez, National of their Fermi surface. The electrical and thermoelectric transport of one Autonomous University of Mexico; R. Kawakami, J.A. Gupta, The Ohio State member of this class, NaSn2As2, will be presented. A second class of University materials have similar transport properties due to different mechanisms: Materials with non-centrosymmetric crystal structures can host helical spin some, like Be and Cd, have Fermi surfaces that contain both electron and states including magnetic skyrmions. Bulk MnGe hosts a short period hole pockets that have partial thermopowers of opposite polarities, but magnetic state (3 nm), whose structure depends strongly on atomic lattice very anisotropic mobilities, so that one carrier type dominates the total strain, and shows a large emergent transport signature associated with the thermopower in one direction, and the other carrier type dominates the skyrmion phase. Here, we use low-temperature (5 K) spin-polarized thermopower in the other direction. A new member of this class, the scanning tunneling microscopy (SP-STM) to image the magnetic textures in semimetal bismuth doped p-type with Sn, will be described in this talks as MnGe thin films grown via molecular beam epitaxy and study the influence well. In practice, a third class of artificial materials made of separate layers of the surface on those textures. Most microscopic locations show a spin of p-type and of n-type semiconductors can be made to have a similar spiral phase with a 6-8 nm period and a propagation direction that is behavior in transport as well; the last two classes are called (pxn)- influenced by step edges and surface termination. We also report the materials. presence of isolated target skyrmions which have a triangular shape that The electrical conductivity and thermopower tensors in goniopolar and appears to be set by the in-plane lattice vectors, and a core size of (pxn) materials can be made to have off-diagonal components, which cause approximately 15 nm. We observe the target state is significantly more exciting new properties like zero-field Hall and Nernst-Ettingshausen sensitive to magnetic fields than the spiral phase, and that local voltage effects. These materials can be used in single-crystal transverse and current pulses with the STM tip imply the texture can be ‘switched’ thermoelectrics. between states with different topological charge. Detailed analysis of atomic resolution STM images is used to probe the role of small lattice [1] He, B. et al , Nat. Mater. (published online doi.org/10.1038/s41563-019- strain on the distinct textures. To fully understand the magnetic textures in 0309, 2019) MnGe we will expand this study by investigating films of different [2] Zhou, C. et al. Phys. Rev. Lett. 110, 227701 (2013). thicknesses to vary the magnetic anisotropy and strain. Funding for this research was provided by the Defense Advanced Research Projects Agency Grant No. 18AP00008 11:00am MI+2D+AS+EM-ThM10 Dzyaloshinskii-Moriya Interaction in Magnetic Multilayers, Hans Nembach, National Institute of Sandards and Technology (NIST) INVITED The Dzyaloshinskii-Moriya Interaction (DMI) gives rise to chiral magnetic structures, which include chiral spin-chains and skyrmions. The latter have recently received much attention, especially for their potential application for magnetic data storage. Each skyrmion would represent a bit and would be moved along a racetrack. DMI requires broken inversion symmetry and can exist in the bulk as well as at interfaces, for example at interfaces between a ferromagnet and a material with large spin-orbit coupling like heavy metals. More recently it has been shown that interfacial DMI can also exist at interfaces with graphene and oxides. We use Brillouin Light Scattering spectroscopy (BLS) to determine the DMI from the non-reciprocal frequency-shift Damon-Eshbach spin-waves. In order to gain deeper insight into the underlying physics of DMI, we prepared several sample series to study different aspects of the DMI. First, we prepared two samples series to study the relationship between the DMI and the Heisenberg exchange. One series was a Ni80Fe20 thickness series on a Pt layer and for the other series we introduced a Cu dusting layer at the interface between a CoFeB layer and Pt to disrupt the Heisenberg exchange directly at the interface. For both sample series, we found that the Heisenberg exchange and the DMI are proportional to each other as it has been predicted by theory. Next, we prepared a Cu/Co90Fe10 and a Pt/Co90Fe10 sample series, which were in-situ oxidized for different times and subsequently capped to prevent any further oxidation. Density functional theory calculations have shown that the hybridization and the associated charge transfer is important for the DMI and that interfaces with an oxide can have DMI. Our BLS measurements showed that oxide interfaces have DMI. Moreover, we showed that the spectroscopic splitting factor g, which we determined with ferromagnetic resonance spectroscopic, is correlated to the DMI. This is an indirect confirmation of the theory predictions regarding the role of hybridization and charge transfer. So far, most work on DMI has been carried out for highly symmetric interfaces. Low symmetry systems can have anisotropic DMI and can Thursday Morning, October 24, 2019 33 8:00 AM Thursday Evening Poster Sessions, October 24, 2019 MI-ThP3 Investigating a Possible Kondo Resonance for Iron-induced Islands on Chromium Nitride (001), K. Alam, Y. Ma, Shyam Chauhan, S.R. Magnetic Interfaces and Nanostructures Division Upadhyay, A.R. Smith, Ohio University Room Union Station B - Session MI-ThP Chromium and iron surfaces have been of intense interest due to their high technological importance. Stroscio et al. investigated the electronic states Magnetic Interfaces and Nanostructures Poster Session of Fe(001) and Cr(001) surfaces using room temperature scanning MI-ThP1 Room Temperature Skyrmion in Alternative Layer Molecular tunneling spectroscopy, finding surface state peaks at +170 meV and -50 meV, respectively, relative to the Fermi level and enabling a chemical Beam Epitaxial Grown B20 Fe-rich Fe1.2Ge Films, Tao Liu, R. Bennett, S. Chen, A. Ahmed, R. Kawakami, The Ohio State University identification of surface elemental species in FeCr alloys.[1] Later, Hanke et al. measured the temperature-dependent spectroscopy on Cr(001) surfaces Magnetic Skyrmions are localized, topological spin textures that arise from competition between exchange interaction and Dzyaloshinskii-Moriya and found that both orbital Kondo effect and single-particle models could be used to reasonably interpret the observed temperature-dependent interaction (DMI) in magnetic materials with broken inversion symmetry. Their topological stability, small size, and the ability to be very energy Cr(001) surface peak seen at 20 meV above E_F.[2] efficiently written, read and manipulated, put them at the forefront of Recently, we have carried out a study of Fe on CrN(001) surfaces exhibiting candidates for next generation storage technology. However, it is still a step-terrace morphology as grown by molecular beam epitaxy. These CrN challenging to find a material which can achieve skyrmion at room samples are antiferromagnetic below 270 K.[3] We performed STS temperature with size no more than 10 nm, which has already become a spectroscopy on, and between, nanometer-sized islands resulting from major bottleneck of their developments. In order to realize this goal, it sub-ML Fe deposition. Spectroscopy on the clean CrN regions displays a requires strong exchange interaction strength J, which sets the broad dip near E_F and a peak at 125 meV, similar to the oxygenated Cr temperature scale, and a large DMI strength D that determines skyrmion surface reported by Hanke et al. Whereas spectroscopy on the islands stability and size, Ja/D (a is the atomic lattice spacing). Current skyrmion displays sharp spectral features exactly at, or within a few meV of, E_F. We research is focused on two classes of materials: metallic multilayers and make a case for interpreting these spectra in terms of a Kondo resonance. B20 crystals. Neither of them can meet this challenge. Metallic multilayers [1] Stroscio et al., Phys. Rev. Lett. 75, 2960 (1995). can meet the criteria of room temperature operations, but with small DMI [2] Hanke et al., Phys. Rev. B 72, 085453 (2005). arising from surface inversion symmetry broken. B20 crystals have a large bulk DMI and nanoscale skyrmions with sizes down to 3 nm, but cannot [3] Alam et al., Phys. Rev. B 96, 104433 (2017). achieve room temperature operations. MI-ThP5 Characteristics of a Single Molecule Magnet on Graphene: A DFT In this work, we successfully synthesized Fe-rich Fe1.2Ge films by alternative Study, Rainier Berkley, Z. Hooshmand, T.S. Rahman, University of Central layer molecular beam epitaxy at room temperature and adding extra Fe Florida atoms at the Fe-sparse atomic layers. As shown in figure 1, the cross Single-molecular magnets (SMMs) are molecules that function as nanoscale sectional TEM result indicated that the Fe-rich Fe1.2Ge film is B20 structure. magnets below their blocking temperature. These systems have become of Its XRD peak position shift to a lower angle relative to FeGe film, which increasing interest due to their potential applications for magnetic might be good evidence indicating the extra Fe atoms went into the B20 technologies, since they display many unique quantum phenomena and structure rather than formed another stucture phase. The Curie their structures can be tuned to modify their magnetic and quantum Temperature of the Fe-rich Fe1.2Ge film has been pushed above room properties. However, in order for SMMs to be applicable for magnetic temperature (RT), and the observing of clear topological Hall resistance technology they must retain stability both in their structures and their with maximum value around H=±1.5 kOe could be the result of stabilization magnetic moments during and after the deposition process. Due to the of RT skymrmion. complicated nature of magnetic interactions with substrates, the effects of magnetic materials on substrates are not fully understood. Therefore, in MI-ThP2 Investigation of Exchange Bias in L10- MnGa/ θ-MnN/MgO Bilayers, Sneha Upadhyay, Ohio University; K. Meng, F.Y. Yang, The Ohio order to fully understand these systems a study of the interactions State University; D. Ingram, A.R. Smith, Ohio University between a well-characterized SMM and substrate at the most fundamental level is required. For this purpose, we have studied the interactions of a Exchange bias, a shift in the center for the magnetic hysteresis loop of a [Mn3]2 dimer1 with graphene using Density Functional Theory (DFT) magnetic material, has gained a lot of attention due to its application in calculations. The [Mn3]2 dimer can exhibit two different ground states: spintronics. Generally, exchange bias is observed in layered magnetic ferromagnetic (FM) and anti-ferromagnetic (AFM). Our calculations for the structure like antiferromagnetic/ferromagnetic bilayers. In this work, the spin of both the FM and AFM configurations of the isolated [Mn3]2 dimers L10 MnGa (Tc= 590K) / θ-MnN (TN= 660K) bilayer on MgO substrate was in gas phase, agree with experimental results (S=12 and 0 respectively)1 studied for the investigation of exchange bias motivated by the recent only when the dimers are charged (+2). More importantly, our calculations report of giant exchange bias using MnN as the antiferromagnet.[1] reveal that graphene is inert; thus, hardly affecting the magnetic properties These bilayers were prepared using molecular beam epitaxy, and the of the FM and AFM dimers and that both dimers display the same spin as in growth was monitored by in-situ RHEED. Three samples were grown with their isolated gas phase structures after deposition. These results are MnN thickness of 47 nm while L10 MnGa thicknesses were varied from further confirmed by charge redistribution analysis in which there are no 15nm, 3nm and 1 nm. During the growth, RHEED images were taken which strong charge distribution from/to molecules to/from graphene and the showed some disorder and roughness on the surfaces especially for thinner spin density remains almost intact after interactions of molecules with ones. In order to observe exchange bias, these samples were field cooled substrate. Our results provide insights into the design of coupled through the Néel temperature and the hysteresis was taken at a specific SMM/substrate systems, namely [Mn3]2 dimer on graphene. applied field using SQUID. The measurements showed the presence of a 1 Nguyen et al. J. Am. Chem. Soc. 2015, 137, 7160−7168. small but finite exchange bias in the case of the 3 nm L10 MnGa/θ-MnN sample in the in-plane direction only, and the amount of loop shift from the * This work is supported by DOE-DE-SC0019330 origin was estimated to be 300 Oersted. The results were compared with MI-ThP6 Molecular Conductivity Switching via Voltage Controlled Spin the recent publication for the case of CoFeB/ θ-MnN which showed giant Crossover at a Ferroelectric Interface, Aaron Mosey, Indiana University- exchange bias (3600 Oersted). Purdue University Indianapolis; G. Hao, University of Nebraska-Lincoln; A.T. Although the field cooling procedure is important to observe exchange N'Diaye, Lawrence Berkeley National Laboratory; A.S. Dale, Indiana bias, in our previous measurements, we were unable to field cool through University-Purdue University Indianapolis; U. Manna, Illinois State the high Néel temperature of MnN. Currently, we are working on a new University; P.A. Dowben, University of Nebraska-Lincoln; R. Cheng, Indiana field cooling capability in our MBE chamber and further plan to study the University-Purdue University Indianapolis sample using in-situ spin-polarized scanning tunneling microscopy under an The scale of new micro and nano magneto-electronic devices is bounded by applied magnetic field. We also plan to repeat the SQUID measurements as thermal and quantum constraints as predicted by Moore’s Relation. This well with the high-temperature, field-cooled sample. necessitates a push into the limits of harnessable natural phenomena to [1] P. Zilske, D. Graulich, M. Dunz, and M. Meinert, "Giant perpendicular facilitate a post-Moore’s era of design. Thermodynamic stability at room exchange bias with antiferromagnetic MnN," Appl. Phys. Lett. 110, 192402 temperature, fast (Ghz) switching, and low energy cost narrow the list of (2017). candidates. Molecular electronic frontier orbital structure of Fe ions in octahedral fields will split in response to the local energetic environment, giving rise to the eg and t•2g• suborbitals. The energetic scale between these Thursday Evening Poster Sessions, October 24, 2019 34 6:30 PM Thursday Evening Poster Sessions, October 24, 2019 two orbitals as a result of this deformation yields a low spin diamagnetic state or an S=2 high spin paramagnetic state. Spin crossover complex [Fe(II)(H2B(pyz)2(bipy))2] will show locking of its spin state well above the transition temperature, with an accompanied change of conductivity, when placed in a polar environment. Here we show voltage controllable, room temperature, stable locking of the spin state, and the corresponding conductivity change, when molecular thin films of [Fe(II)(H2B(pyz)2(bipy))2] are deposited on a ferroelectric polyvinylidene fluoride hexafluropropylene substrate. This opens the door to the creation of a thermodynamically stable, room temperature, multiferroic gated voltage device.

Thursday Evening Poster Sessions, October 24, 2019 35 6:30 PM Author Index Bold page numbers indicate presenter — A — Borchers, J.: TF+EM+MI+MN+OX+PS-MoM3, Corbett, J.P.: MI+2D+AS+EM-ThM3, 32; Abugri, J.B.: TF+EM+MI+MN+OX+PS-MoM6, 4 MI+2D+AS+EM-ThM6, 33 5 Bowden, M.E.: OX+EM+MI+SS-WeM1, 26; Cortes, N.: MI+2D-WeA11, 30 Acosta, A.: MI+2D-WeA10, 29; OX+EM+MI+SS-WeM13, 28 Costine, A.: 2D+AS+MI+NS-TuM6, 11 TF+EM+MI+MN+OX+PS-MoM3, 4 Braun, J.: MI+2D-WeM1, 25 Coultas, S.J.: 2D+AS+MI+NS-TuM12, 12 Adamsen, K.C.: OX+EM+HC+MI+NS+SS+TF- Braun, K.-F.: 2D+AS+MI+NS-WeM12, 21 Counsell, J.D.P.: 2D+AS+MI+NS-TuM12, 12 TuA10, 19 Brédas, J.-L.: 2D+AS+MI+NS-WeM10, 20 Cui, T.: 2D+EM+MI+NS-MoM1, 1 Addou, R.: 2D+AS+MI+NS-TuM11, 12 Brehm, J.: TF+EM+MI+MN+OX+PS-MoM10, Cultrara, N.D.: 2D+EM+MI+MN+NS+QS- Aggarwal, N.: TF+EM+MI-TuM3, 14 5 WeM4, 22; MI+2D+AS+EM-ThM12, 33 Ahmed, A.: MI+2D+AS+EM-ThM3, 32; Brenner, M.: 2D+EM+MI+MN+NS+QS-TuM5, Cunniff, A.: OX+EM+HC+MI+NS+SS+TF- MI+2D+AS+EM-ThM6, 33; MI-ThP1, 34 13 TuA12, 19 Ahsan, R.: EM+2D+AS+MI+MN+NS+TF- Brillson, L.J.: 2D+EM+MI+MN+NS+QS-TuM5, — D — WeM10, 24 13; 2D+EM+MI+NS+QS+SS-ThM10, 31; Dai, Q.: 2D+AS+MI+NS-WeM10, 20 Ajayan, P.M.: 2D+EM+MI+NS-MoM1, 1 EM+2D+AS+MI+MN+NS+TF-WeM2, 23; Dale, A.S.: MI-ThP6, 34 Akaishi, A.: 2D+AP+EM+MI+MN+NS+PS+TF- EM+2D+AS+MI+MN+NS+TF-WeM4, 23 Dardzinsky, D.: 2D+AS+MI+NS-TuM11, 12 MoA9, 8 Brooks, C.: MI+2D-WeM3, 25 Das, H.: MI+2D-WeM3, 25 Alam, K.: MI-ThP3, 34 Brostow, W.: 2D+EM+MI+NS-MoM3, 1 Das, P.K.: 2D+AS+MI+NS-TuM10, 12 Aleithan, S.H.: 2D+EM+MI+NS+QS+SS-ThM5, Bsatee, M.: AC+LS+MI-MoM11, 3 Dasari, R.: 2D+AS+MI+NS-WeM10, 20 31 Bu, H.: TF+EM+MI-TuM11, 16 Datzer, C.: MI+2D-WeM1, 25 Alonso-Mori, R.: AC+LS+MI-MoM9, 3 Budhathoki, S.: MI+2D-WeM12, 26; De Seta, M.: 2D+EM+MI+NS-TuA2, 17 Andersen, T.K.: OX+EM+MI+SS-WeM2, 26 TF+EM+MI+MN+OX+PS-MoM6, 5 Demarest, J.: TF+EM+MI-TuM11, 16 Ando, T.: OX+EM+HC+MI+NS+SS+TF-TuA3, Burg, G.W.: 2D+EM+MI+MN+NS+QS- Demkov, A.A.: OX+EM+MI+SS-WeM3, 27; 18 WeM12, 22 TF+EM+MI-TuM5, 15 Angrick, C.: MI+2D-WeM1, 25 Burkins, P.: TF+EM+MI-TuM6, 15 Dendzik, M.: 2D+AS+MI+NS-TuM10, 12 Annevelink, E.: 2D+EM+MI+NS-MoM10, 2 Buß, L.: 2D+AS+MI+NS-TuM10, 12 Deng, S.: 2D+AS+MI+NS-WeM6, 20 Anwar, F.: OX+EM+MI+SS-WeM12, 27 — C — Desai, J.A.: 2D+EM+MI+NS-MoM4, 1 Arguilla, M.Q.: 2D+EM+MI+MN+NS+QS- Cabrera, G.: MI+2D-WeA12, 30; MI+2D- Di Gaspare, L.: 2D+EM+MI+NS-TuA2, 17 WeM4, 22; MI+2D+AS+EM-ThM12, 33 WeA7, 29 Diebold, A.C.: EM+2D+AS+MI+MN+NS+TF- Astašauskas, V.: 2D+AS+MI+NS-TuM2, 11 Cai, H.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 WeM3, 23 Avalos-Ovando, O.: MI+2D-WeA11, 30 Cakir, D.: 2D+AS+MI+NS-WeM2, 20 Dijkstra, A.: TF+EM+MI-TuM10, 15 — B — Camilli, L.: 2D+EM+MI+NS-TuA2, 17 Dixson, R.G.: EM+2D+AS+MI+MN+NS+TF- Bailey-Crandell, R.: Canulescu, S.: 2D+AP+EM+MI+NS+PS+TF- WeM13, 24 2D+AP+EM+MI+MN+NS+PS+TF-MoA5, 7 MoA3, 9 Donath, M.: MI+2D-WeM1, 25 Bakkers, E.P.A.M.: TF+EM+MI-TuM10, 15 Carman, G.P.: TF+EM+MI+MN+OX+PS- Dong, C.: MI+2D-WeA10, 29; Balasubramanyam, S.: MoM3, 4 TF+EM+MI+MN+OX+PS-MoM3, 4 2D+AP+EM+MI+NS+PS+TF-MoA5, 9 Carr, G.L.: 2D+AS+MI+NS-TuM1, 11 Dowben, P.A.: MI-ThP6, 34; Balke, N.: TF+EM+MI+MN+OX+PS-MoM10, 5 Castell, M.R.: 2D+EM+MI+NS-MoM2, 1 OX+EM+HC+MI+NS+SS+TF-TuA1, 18; Ballard, J.: EM+2D+AS+MI+MN+NS+TF- Catalan, J.A.: 2D+EM+MI+NS-MoM3, 1 OX+EM+MI+SS-WeM12, 27 WeM4, 23 Chae, H.U.: EM+2D+AS+MI+MN+NS+TF- Dravid, V.: 2D+EM+MI+MN+NS+QS-WeM5, Baraldi, A.: 2D+AS+MI+NS-TuM10, 12 WeM10, 24 22 Barral, MA.: 2D+AS+MI+NS-WeM13, 21 Chambers, S.A.: OX+EM+MI+SS-WeM1, 26; Du, D.: TF+EM+MI+MN+OX+PS-MoM11, 5 Barraza-Lopez, S.: 2D+EM+MI+MN+NS+QS- OX+EM+MI+SS-WeM13, 28; Du, Y.: OX+EM+HC+MI+NS+SS+TF-TuA7, 19; TuM6, 13 OX+EM+MI+SS-WeM5, 27 OX+EM+MI+SS-WeM1, 26 Basaldua, I.: TF+EM+MI-TuM6, 15 Chang, J.P.: MI+2D-WeA10, 29; Durfee, C.: TF+EM+MI-TuM11, 16 Basker, V.: TF+EM+MI-TuM11, 16 TF+EM+MI+MN+OX+PS-MoM3, 4 Duscher, G.: 2D+AP+EM+MI+NS+PS+TF- Bassiri-Gharb, N.: TF+EM+MI+MN+OX+PS- Chauhan, S.B.: MI-ThP3, 34 MoA3, 9 MoM8, 5 Chen, I.: 2D+EM+MI+NS-MoM3, 1 — E — Batzill, M.: 2D+EM+MI+NS-TuA11, 18 Chen, J.: 2D+EM+MI+NS+QS+SS-ThM4, 31 Ebert, H.: MI+2D-WeM1, 25 Bauer, E.D.: AC+LS+MI-MoM9, 3 Chen, P.: 2D+EM+MI+NS-MoM2, 1 Edmondson, B.I.: TF+EM+MI-TuM5, 15 Baumbach, R.E.: AC+LS+MI-MoM1, 2 Chen, S.: MI-ThP1, 34 Ekanayaka, T.K.: 2D+EM+MI+NS+QS+SS- Baumgartner, Y.: TF+EM+MI-TuM1, 14 Cheng, R.: MI-ThP6, 34 ThM3, 31 Beach, G.S.D.: TF+EM+MI+MN+OX+PS- Cheon, G.: 2D+EM+MI+MN+NS+QS-WeM1, Ekerdt, J.G.: TF+EM+MI-TuM5, 15 MoM5, 4 21 Eliseev, E.: TF+EM+MI+MN+OX+PS-MoM10, Bechtel, H.A.: 2D+AS+MI+NS-TuM1, 11 Chiang, S.: EM+2D+AS+MI+MN+NS+TF- 5 Bellissimo, A.: 2D+AS+MI+NS-TuM2, 11 WeM12, 24 Elliott, L.C.C.: EM+2D+AS+MI+MN+NS+TF- Belyansky, M.: TF+EM+MI-TuM11, 16 Chien, T.: 2D+EM+MI+NS+QS+SS-ThM3, 31 WeM13, 24 Bennett, R.: MI+2D+AS+EM-ThM6, 33; MI- Chuang, H.-J.: 2D+AP+EM+MI+NS+PS+TF- Emdadi, L.: 2D+AP+EM+MI+MN+NS+PS+TF- ThP1, 34 MoA2, 9; 2D+EM+MI+MN+NS+QS-TuM4, MoA8, 8 Berghuis, W.J.H.: TF+EM+MI-TuM10, 15 13; 2D+EM+MI+NS-TuA7, 17 Enderson, Z.: 2D+AS+MI+NS-WeM10, 20 Berkley, R.: MI-ThP5, 34 Churikova, A.: TF+EM+MI+MN+OX+PS- Engelmann, S.U.: OX+EM+HC+MI+NS+SS+TF- Bertolini, G.: 2D+AS+MI+NS-TuM2, 11 MoM5, 4 TuA3, 18 Bhandari, G.: MI+2D-WeA12, 30; MI+2D- Clark, B.D.: TF+EM+MI+MN+OX+PS-MoM6, 5 Engstrom, J.R.: 2D+AP+EM+MI+NS+PS+TF- WeA7, 29 Cobas, E.D.: 2D+AP+EM+MI+NS+PS+TF- MoA11, 10 Bhattacharya, A.: OX+EM+MI+SS-WeM2, 26 MoA2, 9 Eres, G.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 Bianchi, M.: 2D+AS+MI+NS-TuM10, 12 Cola, B.A.: EM+2D+AS+MI+MN+NS+TF- Eriksson, O.: AC+LS+MI-MoM10, 3 Bignardi, L.: 2D+AP+EM+MI+MN+NS+PS+TF- WeM1, 23 Ertekin, E.: 2D+EM+MI+NS-MoM10, 2 MoA3, 7; 2D+AS+MI+NS-TuM10, 12 Colas, G.: 2D+EM+MI+NS-MoM1, 1 Evans, J.W.: 2D+EM+MI+NS+QS+SS-ThM13, Binek, C.: OX+EM+HC+MI+NS+SS+TF-TuA1, Coletti, C.: 2D+EM+MI+NS-TuA2, 17 32 18 Collette, R.: TF+EM+MI-TuM4, 15 Evans, T.J.: MI+2D-WeM12, 26; MI+2D- Blob, A.: MI+2D-WeM1, 25 Conley, Jr., J.F.: TF+EM+MI-TuM12, 16 WeM13, 26 Blomfield, C.J.: 2D+AS+MI+NS-TuM12, 12 Convertino, C.: TF+EM+MI-TuM1, 14 Ewert, M.: 2D+AS+MI+NS-TuM10, 12 Bol, A.A.: 2D+AP+EM+MI+NS+PS+TF-MoA5, Cook, S.: OX+EM+MI+SS-WeM2, 26 — F — 9 Copeland, C.R.: EM+2D+AS+MI+MN+NS+TF- Fabbri, F.: 2D+EM+MI+NS-TuA2, 17 Booth, C.H.: AC+LS+MI-MoM9, 3 WeM13, 24 Fadaly, E.M.T.: TF+EM+MI-TuM10, 15 Author Index 36 Bold page indicates presenter Author Index

Falta, J.: 2D+AS+MI+NS-TuM10, 12 Hanbicki, A.T.: 2D+AP+EM+MI+NS+PS+TF- — K — Fan, S.: MI+2D-WeM3, 25 MoA2, 9; 2D+EM+MI+MN+NS+QS-TuM4, Kaiser, D.: 2D+AP+EM+MI+NS+PS+TF-MoA9, Faria, D.: 2D+EM+MI+NS-TuA8, 18 13; 2D+EM+MI+NS-TuA7, 17 10 Fatima, F.: 2D+AS+MI+NS-WeM2, 20 Hao, G.: MI-ThP6, 34 Kalinin, S.V.: TF+EM+MI+MN+OX+PS- Feigelson, B.N.: 2D+AP+EM+MI+NS+PS+TF- Hao, S.: 2D+EM+MI+MN+NS+QS-WeM5, 22 MoM10, 5 MoA6, 9 Harsh, B.: 2D+AS+MI+NS-TuM10, 12 Kanatzidis, M.: 2D+EM+MI+MN+NS+QS- Fennie, C.J.: MI+2D-WeM3, 25 Haseman, M.: EM+2D+AS+MI+MN+NS+TF- WeM5, 22 Ferrari, V.: 2D+AS+MI+NS-WeM13, 21 WeM2, 23 Kapadia, R.: EM+2D+AS+MI+MN+NS+TF- Filler, M.A.: EM+2D+AS+MI+MN+NS+TF- Hassani, E.: TF+EM+MI-TuM13, 16 WeM10, 24 WeM1, 23 Haule, K.: 2D+AS+MI+NS-TuM1, 11 Kaspar, T.C.: OX+EM+MI+SS-WeM13, 28 Filleter, T.: 2D+EM+MI+NS-MoM1, 1 Hauser, A.J.: TF+EM+MI+MN+OX+PS-MoM6, Katoch, J.: 2D+EM+MI+NS-TuA9, 18 First, P.N.: 2D+AS+MI+NS-WeM10, 20 5 Kaul, A.B.: 2D+EM+MI+NS-MoM3, 1; Fitzell, K.: MI+2D-WeA10, 29; Haverkort, J.E.M.: TF+EM+MI-TuM10, 15 2D+EM+MI+NS-MoM4, 1 TF+EM+MI+MN+OX+PS-MoM3, 4 Hayden, J.: TF+EM+MI+MN+OX+PS-MoM4, 4 Kawakami, R.: Flege, J.I.: 2D+AS+MI+NS-TuM10, 12 He, B.: 2D+EM+MI+MN+NS+QS-WeM4, 22; 2D+AP+EM+MI+MN+NS+PS+TF-MoA5, 7; Fong, C.Y.: EM+2D+AS+MI+MN+NS+TF- MI+2D+AS+EM-ThM12, 33 2D+EM+MI+MN+NS+QS-TuM5, 13; WeM12, 24 Hellberg, C.S.: 2D+EM+MI+MN+NS+QS- 2D+EM+MI+NS+QS+SS-ThM10, 31; Fong, D.D.: OX+EM+MI+SS-WeM2, 26 TuM4, 13 2D+EM+MI+NS-TuA4, 17; MI+2D+AS+EM- Freeland, J.W.: OX+EM+MI+SS-WeM1, 26 Heremans, J.P.: 2D+EM+MI+MN+NS+QS- ThM6, 33; MI-ThP1, 34 Fu, M.: 2D+AS+MI+NS-TuM6, 11; MI+2D- WeM4, 22; MI+2D+AS+EM-ThM12, 33 Kawasaki, J.: TF+EM+MI+MN+OX+PS- WeM2, 25 Herman, G.S.: 2D+AS+MI+NS-TuM11, 12 MoM11, 5 Fuentes Moyado, S.: 2D+AS+MI+NS-TuM13, Herper, H.C.: AC+LS+MI-MoM10, 3 KC, S.: MI+2D-WeM12, 26; MI+2D-WeM13, 13 Hersam, M.C.: 2D+AS+MI+NS-WeM5, 20; 26 Fujii, J.: 2D+AS+MI+NS-TuM10, 12 2D+EM+MI+NS+QS+SS-ThM1, 31 Kelber, J.A.: 2D+AP+EM+MI+NS+PS+TF- — G — Hillebrands, B.: MI+2D+AS+EM-ThM1, 32 MoA10, 10; OX+EM+MI+SS-WeM12, 27 Gai, Z.: MI+2D-WeM2, 25 Hla, S.-W.: 2D+AS+MI+NS-WeM11, 21; Kessels, W.M.M.: 2D+AP+EM+MI+NS+PS+TF- Galbiati, M.: 2D+EM+MI+NS-TuA2, 17 2D+AS+MI+NS-WeM12, 21 MoA5, 9; TF+EM+MI-TuM10, 15 Gao, H.: EM+2D+AS+MI+MN+NS+TF-WeM2, Hnatchuk, N.: 2D+EM+MI+NS-MoM3, 1 Khadka, S.: 2D+EM+MI+NS+QS+SS-ThM5, 31 23 Hofmann, P.: 2D+AS+MI+NS-TuM10, 12 Khanal, M.P.: TF+EM+MI-TuM13, 16 Gao, H.-J.: 2D+EM+MI+MN+NS+QS-TuM12, Holcomb, M.B.: MI+2D-WeA12, 30; MI+2D- Kim, H-S.: 2D+AS+MI+NS-TuM1, 11 14 WeA7, 29 Kim, J.: 2D+AP+EM+MI+MN+NS+PS+TF- Gao, Y.: 2D+EM+MI+NS-MoM2, 1 Holden, K.E.K.: TF+EM+MI-TuM12, 16 MoA10, 8 Ge, Z.: 2D+EM+MI+MN+NS+QS-TuM10, 13; Holdway, P.: 2D+EM+MI+NS-MoM2, 1 Kim, K.: 2D+EM+MI+MN+NS+QS-WeM12, 22 2D+EM+MI+MN+NS+QS-TuM11, 14; Holinsworth, B.S.: MI+2D-WeM3, 25 Kim, M.J.: TF+EM+MI-TuM5, 15 2D+EM+MI+MN+NS+QS-WeM6, 22 Hollen, S.: 2D+AS+MI+NS-WeM6, 20 King, P.D.C.: 2D+EM+MI+MN+NS+QS-TuM1, Geohegan, D.: 2D+AP+EM+MI+NS+PS+TF- Holtz, M.: MI+2D-WeM3, 25; 13 MoA3, 9 TF+EM+MI+MN+OX+PS-MoM1, 4 Kirby, B.: TF+EM+MI+MN+OX+PS-MoM3, 4 George, A.: 2D+AP+EM+MI+NS+PS+TF- Hong, D.: OX+EM+MI+SS-WeM2, 26 Komninou, P.: TF+EM+MI+MN+OX+PS- MoA9, 10 Hong, H.: OX+EM+MI+SS-WeM2, 26 MoM6, 5 Gerrard, N.: 2D+AS+MI+NS-TuM12, 12 Hooshmand, Z.: MI-ThP5, 34 Korde, M.: EM+2D+AS+MI+MN+NS+TF- Goldberger, J.E.: 2D+EM+MI+MN+NS+QS- Horoz, S.: 2D+EM+MI+NS+QS+SS-ThM3, 31 WeM3, 23 WeM4, 22; MI+2D+AS+EM-ThM12, 33 Hu, B.: MI+2D-WeA8, 29 Kotsonis, G.N.: OX+EM+MI+SS-WeM11, 27 Gopman, D.: TF+EM+MI+MN+OX+PS-MoM3, Huang, C.-Y.: MI+2D-WeA12, 30 Kozak, D.: EM+2D+AS+MI+MN+NS+TF- 4 Huang, P.Y.: 2D+EM+MI+NS-MoM10, 2 WeM13, 24 Goswami, L.: TF+EM+MI-TuM3, 14 Hübner, U.: 2D+AP+EM+MI+NS+PS+TF- Krishna, S.: TF+EM+MI-TuM3, 14 Gougousi, T.: TF+EM+MI-TuM6, 15 MoA9, 10 Kroll, T.: AC+LS+MI-MoM9, 3 Gowda, R.G.: EM+2D+AS+MI+MN+NS+TF- Huhtinen, H.: AC+LS+MI-MoM11, 3; Kropp, J.A.: TF+EM+MI-TuM6, 15 WeM3, 23 OX+EM+HC+MI+NS+SS+TF-TuA11, 19 Kuis, R.: TF+EM+MI-TuM6, 15 Greer, J.: TF+EM+MI+MN+OX+PS-MoM5, 4 Hunt, D.: 2D+AS+MI+NS-WeM13, 21 Kumari, S.: MI+2D-WeA12, 30 Grundmann, M.: Hwang, J.: 2D+EM+MI+MN+NS+QS-TuM5, 13 Kwon, S.: TF+EM+MI-TuM5, 15 EM+2D+AS+MI+MN+NS+TF-WeM2, 23 — I — — L — Grzeskowiak, J.: 2D+AS+MI+NS-TuM5, 11 Ilic, B.R.: EM+2D+AS+MI+MN+NS+TF- Lacovig, P.: 2D+AP+EM+MI+MN+NS+PS+TF- Gu, Y.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 WeM13, 24 MoA3, 7; 2D+AS+MI+NS-TuM10, 12 Guerrero-Sanchez, J.: MI+2D+AS+EM-ThM6, Inbanathan, F.P.N.: AC+LS+MI-MoM11, 3 Ladewig, C.: OX+EM+MI+SS-WeM12, 27 33 Ingram, D.: MI-ThP2, 34 Lai, K.C.: 2D+EM+MI+NS+QS+SS-ThM13, 32 Guo, D.: TF+EM+MI-TuM11, 16 — J — Larciprete, R.: Gupta, A.: MI+2D-WeM12, 26 Jamer, M.E.: TF+EM+MI+MN+OX+PS-MoM3, 2D+AP+EM+MI+MN+NS+PS+TF-MoA3, 7; Gupta, G.: TF+EM+MI-TuM3, 14 4 2D+AS+MI+NS-TuM10, 12 Gupta, J.A.: 2D+AS+MI+NS-WeM6, 20; Jariwala, D.: 2D+EM+MI+NS-MoM8, 1 Latgé, A.: 2D+EM+MI+NS-TuA8, 18 2D+EM+MI+MN+NS+QS-TuM5, 13; Jarry, A.: EM+2D+AS+MI+MN+NS+TF-WeM4, Latt, K.Z.: 2D+AS+MI+NS-WeM11, 21 MI+2D+AS+EM-ThM3, 32; MI+2D+AS+EM- 23 Lauritsen, J.V.: ThM6, 33 Jensen, G.: 2D+EM+MI+NS+QS+SS-ThM5, 31 2D+AP+EM+MI+MN+NS+PS+TF-MoA6, 8; Gupta, S.: TF+EM+MI+MN+OX+PS-MoM6, 5 Jernigan, G.: 2D+EM+MI+NS-TuA7, 17 OX+EM+HC+MI+NS+SS+TF-TuA10, 19 Gürlü, O.: 2D+AS+MI+NS-TuM2, 11 Jesse, S.: TF+EM+MI+MN+OX+PS-MoM10, 5 LaVoie, A.: 2D+AP+EM+MI+NS+PS+TF- Gurung, G.: 2D+EM+MI+NS+QS+SS-ThM3, 31 Jiang, L.: TF+EM+MI-TuM11, 16 MoA10, 10 Gustafson, M.E.: Johnson, A.M.: TF+EM+MI-TuM6, 15 LeClair, P.: MI+2D-WeM12, 26 EM+2D+AS+MI+MN+NS+TF-WeM1, 23 Jones, J.: 2D+AP+EM+MI+NS+PS+TF-MoA10, Lee, H.: TF+EM+MI-TuM13, 16 — H — 10 Lee, I.: 2D+AP+EM+MI+MN+NS+PS+TF- Haastrup, M.J.: Jonker, B.T.: 2D+AP+EM+MI+NS+PS+TF- MoA8, 8 2D+AP+EM+MI+MN+NS+PS+TF-MoA6, 8 MoA2, 9; 2D+EM+MI+MN+NS+QS-TuM4, León, C.: 2D+EM+MI+NS-TuA8, 18 Haglund, A.V.: 2D+AS+MI+NS-TuM1, 11 13; 2D+EM+MI+NS-TuA4, 17; Li, A.-P.: MI+2D-WeM2, 25 Haigh, S.: 2D+AS+MI+NS-TuM3, 11 2D+EM+MI+NS-TuA7, 17 Li, H.: 2D+AS+MI+NS-WeM10, 20 Han, E.: 2D+EM+MI+NS-MoM10, 2 Jose Yacaman, M.: 2D+AS+MI+NS-TuM13, 13 Li, J.: TF+EM+MI-TuM11, 16 Han, Y.: 2D+EM+MI+NS+QS+SS-ThM13, 32 Julien, S.: 2D+EM+MI+NS+QS+SS-ThM13, 32 Li, L.: MI+2D-WeM2, 25

Author Index 37 Bold page indicates presenter Author Index

Li, L.L.: 2D+EM+MI+MN+NS+QS-TuM10, 13; Mchenry, M.: MI+2D-WeM10, 25 Orvis, T.: OX+EM+HC+MI+NS+SS+TF-TuA12, 2D+EM+MI+MN+NS+QS-TuM11, 14; Meng, K.: 2D+AS+MI+NS-WeM13, 21; 19 2D+EM+MI+MN+NS+QS-WeM6, 22 MI+2D+AS+EM-ThM3, 32; MI-ThP2, 34 — P — Li, S.: 2D+AS+MI+NS-WeM5, 20 Merkx, M.J.M.: 2D+AP+EM+MI+NS+PS+TF- Paik, H.: TF+EM+MI+MN+OX+PS-MoM11, 5 Liang, L.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 MoA5, 9 Palai, R.: AC+LS+MI-MoM11, 3; Liao, K.-T.: EM+2D+AS+MI+MN+NS+TF- Mewes, T.: MI+2D-WeM13, 26 OX+EM+HC+MI+NS+SS+TF-TuA11, 19 WeM13, 24 Michiardi, M.: 2D+AS+MI+NS-TuM10, 12 Pana, A.: TF+EM+MI-TuM11, 16 Liddle, J.A.: EM+2D+AS+MI+MN+NS+TF- Miller, B.: 2D+EM+MI+MN+NS+QS-TuM6, 13 Pandit, A.: 2D+EM+MI+MN+NS+QS-TuM6, WeM13, 24 Miseikis, V.: 2D+EM+MI+NS-TuA2, 17 13 Lii-Rosales, A.: 2D+EM+MI+NS+QS+SS- Moffitt, C.: 2D+AS+MI+NS-TuM12, 12 Pantelides, S.: TF+EM+MI+MN+OX+PS- ThM13, 32 Morozovska, A.N.: TF+EM+MI+MN+OX+PS- MoM10, 5 Lima, L.: 2D+EM+MI+NS-TuA8, 18 MoM10, 5 Park, M.: TF+EM+MI-TuM13, 16 Lin, E.: TF+EM+MI-TuM5, 15 Moselund, K.E.: TF+EM+MI-TuM1, 14 Parker, D.S.: MI+2D-WeM2, 25 Lin, Y-C.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 Mosey, A.: MI-ThP6, 34 Parker, T.C.: 2D+AS+MI+NS-WeM10, 20 Liu, C.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9; Mottaghi, N.M.: MI+2D-WeA12, 30; MI+2D- Pasquale, F.: 2D+AP+EM+MI+NS+PS+TF- OX+EM+MI+SS-WeM2, 26 WeA7, 29 MoA10, 10 Liu, L.: 2D+EM+MI+MN+NS+QS-WeM6, 22 Movva, H.C.P.: 2D+EM+MI+MN+NS+QS- Paudel, T.: 2D+EM+MI+NS+QS+SS-ThM3, 31 Liu, T.: 2D+EM+MI+MN+NS+QS-TuM5, 13; WeM12, 22 Perez, P.: 2D+EM+MI+NS-MoM3, 1 MI+2D+AS+EM-ThM6, 33; MI-ThP1, 34 Mueller, S.M.: 2D+AS+MI+NS-WeM6, 20 Persichetti, L.: 2D+EM+MI+NS-TuA2, 17 Liu, X.: 2D+AS+MI+NS-WeM5, 20 Mukherjee, S.: 2D+EM+MI+NS-MoM1, 1 Pescia, D.: 2D+AS+MI+NS-TuM2, 11 Liu, Y.: OX+EM+HC+MI+NS+SS+TF-TuA12, 19 Mukundan, V.: EM+2D+AS+MI+MN+NS+TF- Pierantozzi, G.M.: 2D+AS+MI+NS-TuM2, 11 Lizzit, D.: 2D+AP+EM+MI+MN+NS+PS+TF- WeM3, 23 Pilli, A.: 2D+AP+EM+MI+NS+PS+TF-MoA10, MoA3, 7; 2D+AS+MI+NS-TuM10, 12 Muller, D.A.: MI+2D-WeM3, 25 10 Lizzit, S.: 2D+AP+EM+MI+MN+NS+PS+TF- Mundy, J.A.: MI+2D-WeM3, 25 Pintar, A.: EM+2D+AS+MI+MN+NS+TF- MoA3, 7; 2D+AS+MI+NS-TuM10, 12 Mupparapu, R.: 2D+AP+EM+MI+NS+PS+TF- WeM13, 24 Luican-Mayer, A.: 2D+EM+MI+NS+QS+SS- MoA9, 10 Pookpanratana, S.: ThM11, 32 Murali, H.: 2D+AS+MI+NS-WeM10, 20 EM+2D+AS+MI+MN+NS+TF-WeM11, 24 Luo, Y.K.: 2D+EM+MI+NS-TuA4, 17 Musfeldt, J.L.: 2D+AS+MI+NS-TuM1, 11; Poudel, S.: 2D+EM+MI+MN+NS+QS-TuM6, Luo, YK.: 2D+AP+EM+MI+MN+NS+PS+TF- MI+2D-WeM3, 25 13 MoA5, 7 Myung, J.-H.: EM+2D+AS+MI+MN+NS+TF- Premarathna, S.: 2D+AS+MI+NS-WeM11, 21 Lyalin, I.: 2D+AP+EM+MI+MN+NS+PS+TF- WeM13, 24 Pronin, N.: EM+2D+AS+MI+MN+NS+TF- MoA5, 7 — N — WeM4, 23 — M — Naczas, S.: TF+EM+MI-TuM11, 16 Puretzky, A.A.: 2D+AP+EM+MI+NS+PS+TF- Ma, Y.: 2D+AS+MI+NS-WeM13, 21; MI-ThP3, Nakamura, J.N.: MoA3, 9 34 2D+AP+EM+MI+MN+NS+PS+TF-MoA9, 8 — Q — Mackus, A.J.M.: 2D+AP+EM+MI+NS+PS+TF- Nam, C.Y.: TF+EM+MI-TuM13, 16 Qi, Y.: TF+EM+MI-TuM12, 16 MoA5, 9 Narayanan, V.: OX+EM+HC+MI+NS+SS+TF- — R — Madison, A.C.: EM+2D+AS+MI+MN+NS+TF- TuA3, 18 Rack, P.D.: 2D+AP+EM+MI+NS+PS+TF-MoA3, WeM13, 24 N'Diaye, A.T.: MI-ThP6, 34 9; TF+EM+MI-TuM4, 15 Mahat, R.: MI+2D-WeM12, 26 Neal, S.N.: 2D+AS+MI+NS-TuM1, 11 Rahman, T.S.: EM+2D+AS+MI+MN+NS+TF- Mahmud, M.T.: 2D+EM+MI+NS-TuA3, 17 Nembach, H.: MI+2D+AS+EM-ThM10, 33 WeM12, 24; MI-ThP5, 34 Mahoney, L.: Neto, P.: 2D+EM+MI+NS-TuA11, 18 Rahn, M.: 2D+AS+MI+NS-WeM5, 20 2D+AP+EM+MI+MN+NS+PS+TF-MoA8, 8 Neumann, C.: 2D+AP+EM+MI+NS+PS+TF- Ramesh, R.: MI+2D-WeM3, 25 Maksymovych, P.: TF+EM+MI+MN+OX+PS- MoA9, 10 Ramsperger, U.: 2D+AS+MI+NS-TuM2, 11 MoM10, 5 Neumayer, S.: TF+EM+MI+MN+OX+PS- Randeria, M.: MI+2D+AS+EM-ThM3, 32 Mammen, M.: MoM10, 5 Rath, S.: 2D+EM+MI+NS-TuA12, 18 2D+AP+EM+MI+MN+NS+PS+TF-MoA6, 8 Neupane, M.: Ravichandran, J.: OX+EM+HC+MI+NS+SS+TF- Mandrus, D.G.: 2D+AS+MI+NS-TuM1, 11 2D+AP+EM+MI+MN+NS+PS+TF-MoA5, 7 TuA12, 19 Mankey, G.J.: MI+2D-WeM12, 26; MI+2D- Newburger, M.: Rebola, A.F.: MI+2D-WeM3, 25 WeM13, 26 2D+AP+EM+MI+MN+NS+PS+TF-MoA5, 7; Reed, E.J.: 2D+EM+MI+MN+NS+QS-WeM1, Manna, U.: MI-ThP6, 34 2D+EM+MI+NS-TuA4, 17 21 Marder, S.R.: 2D+AS+MI+NS-WeM10, 20 Newhouse-Illige, T.: TF+EM+MI+MN+OX+PS- Reimann, A.: MI+2D-WeM1, 25 Maria, J.-P.: OX+EM+MI+SS-WeM11, 27; MoM5, 4 Reinke, P.: 2D+AS+MI+NS-TuM6, 11 TF+EM+MI+MN+OX+PS-MoM4, 4 Nguyen, V.: 2D+AP+EM+MI+MN+NS+PS+TF- Rementer, C.R.: TF+EM+MI+MN+OX+PS- Martin, I.: 2D+EM+MI+NS-TuA4, 17 MoA4, 7 MoM3, 4 Martinazzo, R.: Nguyen-Cong, K.: 2D+EM+MI+NS-TuA11, 18 Repicky, J.J.: 2D+EM+MI+MN+NS+QS-TuM5, 2D+AP+EM+MI+MN+NS+PS+TF-MoA3, 7 Nicholls, D.: 2D+AS+MI+NS-WeM2, 20 13; MI+2D+AS+EM-ThM3, 32; Martínez, R.: AC+LS+MI-MoM11, 3 Noesges, B.A.: 2D+EM+MI+MN+NS+QS- MI+2D+AS+EM-ThM6, 33 Matos-Abiague, A.: TuM5, 13; 2D+EM+MI+NS+QS+SS-ThM10, Rezaeifar, F.R.: EM+2D+AS+MI+MN+NS+TF- 2D+AP+EM+MI+MN+NS+PS+TF-MoA5, 7 31 WeM10, 24 Matsuyama, H.: Nordlund, D.: AC+LS+MI-MoM9, 3 Ridzel, O.: 2D+AS+MI+NS-TuM2, 11 2D+AP+EM+MI+MN+NS+PS+TF-MoA9, 8 Notargiacomo, A.: 2D+EM+MI+NS-TuA2, 17 Rimal, G.: 2D+EM+MI+NS+QS+SS-ThM3, 31 Mauthe, S.: TF+EM+MI-TuM1, 14 Nowak, S.: AC+LS+MI-MoM9, 3 Roberts, A.J.: 2D+AS+MI+NS-TuM12, 12 Mazin, I.I.: 2D+EM+MI+MN+NS+QS-TuM4, Nyakiti, L.O.: 2D+AP+EM+MI+NS+PS+TF- Robey, S.W.: EM+2D+AS+MI+MN+NS+TF- 13 MoA6, 9 WeM11, 24 Mazumder, S.: 2D+EM+MI+NS-MoM3, 1; — O — Rodríguez-Fernández, J.: 2D+EM+MI+NS-MoM4, 1 Oh, T.S.: TF+EM+MI-TuM13, 16 2D+AP+EM+MI+MN+NS+PS+TF-MoA6, 8 McCormick, E.: 2D+EM+MI+NS-TuA4, 17 O'Hara, D.: 2D+EM+MI+MN+NS+QS-TuM5, Rojas, T.: 2D+EM+MI+MN+NS+QS-WeM10, McCreary, K.M.: 2D+AP+EM+MI+NS+PS+TF- 13; 2D+EM+MI+NS+QS+SS-ThM10, 31 22 MoA2, 9; 2D+EM+MI+MN+NS+QS-TuM4, Ohta, T.: EM+2D+AS+MI+MN+NS+TF- Rosales, L.: MI+2D-WeA11, 30 13; 2D+EM+MI+NS-TuA4, 17; WeM11, 24 Rosenberger, M.R.: 2D+EM+MI+NS-TuA7, 17 Okuda, T.: MI+2D-WeM5, 25 2D+AP+EM+MI+NS+PS+TF-MoA2, 9; McGill, S.A.: MI+2D-WeM3, 25 Oleynik, I.I.: 2D+EM+MI+NS-TuA11, 18 2D+EM+MI+MN+NS+QS-TuM4, 13; McGuire, M.A.: TF+EM+MI+MN+OX+PS- Oncel, N.: 2D+AS+MI+NS-WeM2, 20 2D+EM+MI+NS-TuA7, 17 MoM10, 5 Orellana, P.: MI+2D-WeA11, 30

Author Index 38 Bold page indicates presenter Author Index

Rouleau, C.M.: 2D+AP+EM+MI+NS+PS+TF- Sun, Y.: 2D+EM+MI+NS-MoM1, 1 Wang, Y.: 2D+AS+MI+NS-WeM6, 20; MoA3, 9 Surendran, M.: OX+EM+HC+MI+NS+SS+TF- 2D+EM+MI+MN+NS+QS-WeM4, 22; Rowland, J.: MI+2D+AS+EM-ThM3, 32 TuA12, 19 MI+2D+AS+EM-ThM12, 33; Rubloff, G.W.: EM+2D+AS+MI+MN+NS+TF- Susner, M.A.: TF+EM+MI+MN+OX+PS- TF+EM+MI+MN+OX+PS-MoM3, 4 WeM4, 23 MoM10, 5 Warner, J.H.: 2D+EM+MI+NS-MoM2, 1 Ruocco, A.: 2D+AS+MI+NS-TuM2, 11 — T — Weinert, M.: 2D+EM+MI+MN+NS+QS- — S — Taborelli, M.: 2D+AS+MI+NS-TuM2, 11 TuM10, 13; 2D+EM+MI+MN+NS+QS- Safat, A.: MI+2D-WeM2, 25 Tam, J.: 2D+EM+MI+NS-MoM1, 1 WeM6, 22 Sanders, C.E.: 2D+AS+MI+NS-TuM10, 12 Tang, J.: 2D+EM+MI+NS+QS+SS-ThM3, 31 Weitering, H.: 2D+EM+MI+NS+QS+SS-ThM6, Sandler, N.: 2D+EM+MI+NS-TuA3, 17; Tang, Z.: 2D+AP+EM+MI+NS+PS+TF-MoA9, 31 2D+EM+MI+NS-TuA8, 18 10 Wendt, S.: OX+EM+HC+MI+NS+SS+TF- Sapkota, A.: MI+2D-WeM13, 26 Taylor, H.: 2D+AP+EM+MI+MN+NS+PS+TF- TuA10, 19 Sarwar, S.: TF+EM+MI-TuM13, 16 MoA4, 7 Weng, T.C.: AC+LS+MI-MoM9, 3 Scaparro, A.: 2D+EM+MI+NS-TuA2, 17 Taylor, S.D.: OX+EM+MI+SS-WeM13, 28 Werner, W.S.M.: 2D+AS+MI+NS-TuM2, 11 Schlom, D.G.: MI+2D-WeM3, 25; Tervo, E.J.: EM+2D+AS+MI+MN+NS+TF- Wickramasinghe, T.E.: TF+EM+MI+MN+OX+PS-MoM1, 4 WeM1, 23 2D+EM+MI+NS+QS+SS-ThM5, 31 Schmid, H.: TF+EM+MI-TuM1, 14 Thiel, P.A.: 2D+EM+MI+NS+QS+SS-ThM13, Wiesendanger, R.M.: 2D+AS+MI+NS-WeM3, Schmidt, G.: MI+2D+AS+EM-ThM4, 32 32 20 Schneider, D.J.: TF+EM+MI+MN+OX+PS- Thomas, S.: 2D+AS+MI+NS-WeM10, 20 Windl, W.: 2D+AS+MI+NS-WeM6, 20; MoM3, 4 Thorat, R.: 2D+EM+MI+NS+QS+SS-ThM5, 31 2D+EM+MI+MN+NS+QS-WeM4, 22; Schreiber, D.K.: OX+EM+MI+SS-WeM13, 28 Thunström, P.: AC+LS+MI-MoM10, 3 MI+2D+AS+EM-ThM12, 33 Schwartz, J.: TF+EM+MI+MN+OX+PS-MoM4, Tiwari, P.: TF+EM+MI-TuM1, 14 Winter, A.: 2D+AP+EM+MI+NS+PS+TF- 4 Tobin, J.G.: AC+LS+MI-MoM9, 3 MoA9, 10 Scipioni, L.: TF+EM+MI+MN+OX+PS-MoM5, Tran, D.: 2D+AP+EM+MI+MN+NS+PS+TF- Wollmershauser, J.A.: 4 MoA8, 8 2D+AP+EM+MI+NS+PS+TF-MoA6, 9 Scudder, M.R.: 2D+EM+MI+MN+NS+QS- Trappen, R.B.: MI+2D-WeA12, 30; MI+2D- Wolverton, C.: 2D+EM+MI+MN+NS+QS- WeM4, 22; MI+2D+AS+EM-ThM12, 33 WeA7, 29 WeM5, 22 Scurti, F.: TF+EM+MI+MN+OX+PS-MoM4, 4 Travaglia, E.: 2D+AS+MI+NS-TuM10, 12 Wormington, M.: Seehra, M.S.S.: MI+2D-WeA12, 30; MI+2D- Tringides, M.C.: 2D+EM+MI+NS+QS+SS- EM+2D+AS+MI+MN+NS+TF-WeM3, 23 WeA7, 29 ThM13, 32 Wrobel, F.: OX+EM+MI+SS-WeM2, 26 Shah, S.Q.A.: OX+EM+MI+SS-WeM12, 27 Trioni, M.I.: 2D+AP+EM+MI+MN+NS+PS+TF- Wu, Y.: TF+EM+MI-TuM4, 15 Shekhawat, G.: 2D+EM+MI+MN+NS+QS- MoA3, 7 Wu, Z.: MI+2D-WeM2, 25 WeM5, 22 Tu, Q.: 2D+EM+MI+MN+NS+QS-WeM5, 22 — X — Shepard, A.: TF+EM+MI+MN+OX+PS-MoM5, Turchanin, A.: 2D+AP+EM+MI+NS+PS+TF- Xiao, K.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 4 MoA9, 10 Xie, R.K.: EM+2D+AS+MI+MN+NS+TF- Si, M.: 2D+EM+MI+MN+NS+QS-WeM3, 21 Tutuc, E.: 2D+EM+MI+MN+NS+QS-WeM12, WeM12, 24 Siddiqui, S.: TF+EM+MI-TuM11, 16 22 Xing, H.Z.: EM+2D+AS+MI+MN+NS+TF- Singh, C.V.: 2D+EM+MI+NS-MoM1, 1 — U — WeM12, 24 Singh, D.: MI+2D-WeA1, 29 Uhlir, V.: MI+2D-WeA3, 29 Xu, T.: OX+EM+HC+MI+NS+SS+TF-TuA10, 19 Singh, V.: 2D+EM+MI+NS-TuA12, 18 Ulloa, S.: 2D+EM+MI+MN+NS+QS-WeM10, Xu, W.: 2D+EM+MI+NS-MoM2, 1 Sivaram, S.V.: 2D+EM+MI+MN+NS+QS- 22; MI+2D-WeA11, 30 Xu, X.: OX+EM+HC+MI+NS+SS+TF-TuA1, 18 TuM4, 13; 2D+EM+MI+NS-TuA7, 17 Upadhyay, S.R.: MI-ThP2, 34; MI-ThP3, 34 — Y — Smith, A.R.: 2D+AS+MI+NS-WeM13, 21; MI- Uprety, S.: TF+EM+MI-TuM13, 16 Yakobson, B.: 2D+AS+MI+NS-WeM5, 20 ThP2, 34; MI-ThP3, 34 Ushirozako, M.: Yalisove, R.: 2D+AP+EM+MI+NS+PS+TF- Smith, K.A.: 2D+AS+MI+NS-TuM1, 11; 2D+AP+EM+MI+MN+NS+PS+TF-MoA9, 8 MoA11, 10 MI+2D-WeM3, 25 — V — Yan, C.: 2D+EM+MI+MN+NS+QS-TuM11, 14; Smith, S.: 2D+EM+MI+NS+QS+SS-ThM6, 31 van der Zande, A.M.: 2D+EM+MI+MN+NS+QS-WeM6, 22 Sokaras, D.: AC+LS+MI-MoM9, 3 2D+AP+EM+MI+MN+NS+PS+TF-MoA1, 7; Yang, F.Y.: 2D+AS+MI+NS-WeM13, 21; Son, J.: 2D+EM+MI+NS-MoM10, 2 2D+EM+MI+NS-MoM10, 2 2D+EM+MI+MN+NS+QS-TuM5, 13; Song, Y.: TF+EM+MI-TuM11, 16 Vanderbilt, D.: 2D+AS+MI+NS-TuM1, 11 AC+LS+MI-MoM3, 2; MI+2D+AS+EM-ThM3, Sousa, N.: TF+EM+MI-TuM1, 14 Vekilova, O.Y.: AC+LS+MI-MoM10, 3 32; MI-ThP2, 34 Spanopoulos, I.: 2D+EM+MI+MN+NS+QS- Ventrice, Jr., C.A.: 2D+AS+MI+NS-TuM5, 11 Yang, Z.: OX+EM+MI+SS-WeM1, 26 WeM5, 22 Verheijen, M.A.: TF+EM+MI-TuM10, 15 Yao, Z.: TF+EM+MI+MN+OX+PS-MoM3, 4 Spurgeon, S.R.: OX+EM+MI+SS-WeM13, 28 Vicente, J.: 2D+EM+MI+NS+QS+SS-ThM4, 31 Ye, P.: 2D+EM+MI+MN+NS+QS-WeM3, 21 Sridhara, K.: 2D+AP+EM+MI+NS+PS+TF- Vico Trivino, N.: TF+EM+MI-TuM1, 14 Yoon, M.: 2D+AP+EM+MI+NS+PS+TF-MoA3, MoA6, 9 Villanova, J.: 2D+EM+MI+MN+NS+QS-TuM6, 9 St. Laurent, B.: 2D+AS+MI+NS-WeM6, 20 13 Yost, A.J.: 2D+EM+MI+NS+QS+SS-ThM3, 31 Staude, I.: 2D+AP+EM+MI+NS+PS+TF-MoA9, Visscher, P.B.: TF+EM+MI+MN+OX+PS- Yousefi Sarraf, S.: MI+2D-WeA12, 30 10 MoM6, 5 Yousefi, S.F.: MI+2D-WeA7, 29 Staudinger, P.: TF+EM+MI-TuM1, 14 Vobornik, I.: 2D+AS+MI+NS-TuM10, 12 Yu, J.: 2D+EM+MI+NS-MoM10, 2 Stavis, S.M.: EM+2D+AS+MI+MN+NS+TF- Volders, C.: 2D+AS+MI+NS-TuM6, 11 Yu, S.: 2D+EM+MI+MN+NS+QS-TuM5, 13 WeM13, 24 von Wenckstern, H.: Yu, S.W.: AC+LS+MI-MoM9, 3 Stefani, G.: 2D+AS+MI+NS-TuM2, 11 EM+2D+AS+MI+MN+NS+TF-WeM2, 23 Yu, Y.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 Stinaff, E.: 2D+EM+MI+NS+QS+SS-ThM5, 31 Voyles, P.: TF+EM+MI+MN+OX+PS-MoM11, — Z — Strasser, A.: 2D+AP+EM+MI+NS+PS+TF- 5 Zepeda, T.: 2D+AS+MI+NS-TuM13, 13 MoA3, 9 — W — Zhang, C.: TF+EM+MI+MN+OX+PS-MoM11, 5 Strohbeen, P.: TF+EM+MI+MN+OX+PS- Walker, M.: EM+2D+AS+MI+MN+NS+TF- Zhang, H.: 2D+EM+MI+MN+NS+QS-TuM10, MoM11, 5 WeM4, 23 13; 2D+EM+MI+MN+NS+QS-TuM11, 14; Stuckert, E.P.: TF+EM+MI-TuM11, 16 Wan, K.-T.: 2D+EM+MI+NS+QS+SS-ThM13, 2D+EM+MI+MN+NS+QS-WeM6, 22 Subramanian, A.: TF+EM+MI-TuM13, 16 32 Zhang, W.: 2D+AP+EM+MI+NS+PS+TF-MoA3, Sudeep, P.M.: 2D+EM+MI+NS-MoM1, 1 Wang, K.: 2D+AP+EM+MI+NS+PS+TF-MoA3, 9 Suh, T.: 2D+AP+EM+MI+NS+PS+TF-MoA11, 9 Zhang, X.: TF+EM+MI-TuM13, 16 10 Wang, L.: 2D+AS+MI+NS-WeM5, 20; Zhang, Y.: 2D+AS+MI+NS-WeM12, 21 Sun, N.: TF+EM+MI+MN+OX+PS-MoM3, 4 OX+EM+MI+SS-WeM1, 26 Zhang, Z.M.: EM+2D+AS+MI+MN+NS+TF- Sun, N.X.S.: MI+2D-WeA10, 29 Wang, S.: 2D+AS+MI+NS-WeM12, 21 WeM1, 23

Author Index 39 Bold page indicates presenter Author Index

Zheng, L.: MI+2D+AS+EM-ThM12, 33 Zhu, T.: 2D+EM+MI+MN+NS+QS-TuM5, 13; Zurbuchen, M.: MI+2D-WeA10, 29 Zhou, T.: 2D+AP+EM+MI+MN+NS+PS+TF- 2D+EM+MI+NS+QS+SS-ThM10, 31 Zutic, I.: 2D+AP+EM+MI+MN+NS+PS+TF- MoA5, 7 Zieve, R.J.: AC+LS+MI-MoM5, 2 MoA5, 7 Zhu, M.: 2D+EM+MI+MN+NS+QS-TuM5, 13 Zou, Q.: 2D+EM+MI+MN+NS+QS-TuM11, 14; Zwicknagl, G.E.: AC+LS+MI-MoM8, 3 MI+2D-WeM2, 25

Author Index 40 Bold page indicates presenter